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Vaxart Oral Pill Bivalent Norovirus Vaccine Clinical Trials, Dosage, Indication, News, Side Effects

Vaxart Inc.'s GI.1/GII.4 oral pill bivalent norovirus vaccine candidate, consisting of monovalent GII.4 VXA-G2.4-NS and GI.1 VXA-G1.1-NN, is designed to prevent illness from norovirus, a very contagious virus that causes vomiting and diarrhea. Norovirus GI.1 Norwalk VP1 Vaccine (VXA-G1.1-NN), an Oral E1/E3-Deleted Replication-Defective Recombinant Adenovirus serotype 5 with double-stranded ribonucleic acid (dsRNA) Adjuvant. The vaccine vector encodes for a full-length VP1 gene from the Norwalk virus (NV). The adjuvant is a short hairpin RNA (shRNA), expressed as a 21-nucleotide sequence (GAAACGA TATGGGCTGAATAC) in tandem, with the forward and reverse orientations separated by six nucleotides that comprise the loop of the RNA. The final drug product is formulated into an enteric-coated tablet. Vaxart's vaccine is differentiated from other norovirus candidates because it generates both systemic and mucosal immunity, delivered through the mouth, and is stable at room temperature.

Vaxart reported topline data from the Phase 1 clinical trial, which focused on lactating mothers, on April 30, 2024. In the breast milk of lactating mothers who received the Vaxart vaccine candidate in the high-dose group, antibodies to norovirus increased on average fourfold for the G1.1 virus strain and sixfold for the GII.4 virus strain. There were no vaccine-related serious adverse events, and no dose-limiting pharmacotoxicity was observed.

On March 6, 2025, Vaxart announced that data from the Phase 1b trial in elderly adults (55-80 years), which show strong and durable antibody responses and induction of norovirus-specific antibody and T cell responses, support the vaccine candidate's immunogenicity in a patient population that often has age-related reductions in immune reactions to injected vaccines. On May 14, 2025, Vaxart announced the publication of complete data from a Phase 2b challenge study of its first-generation oral pill norovirus vaccine candidate (NCT05212168) in Science Translational Medicine. Consistent with preliminary data reported in September 2023, the complete results show that the trial met five of its six primary endpoints and demonstrate the safety, efficacy, and immunogenicity of the vaccine candidate. Additional data included in the current publication include results from machine learning analyses that identify functional blocking antibody and fecal IgA as robust correlates of protection. These additional results will help inform the development of the Company’s second-generation oral pill norovirus vaccine candidate.

South San Francisco, CA-based Vaxart Inc. is a clinical-stage biotechnology company developing a range of oral recombinant vaccines based on its proprietary delivery platform. Vaxart believes that a vaccine that produces mucosal antibodies locally in the intestine and systemic antibodies circulating in the blood may offer better protection against norovirus infection than an injectable vaccine.

Vaxart Oral Bivalent Norovirus Vaccine Indication

Norovirus is the leading cause of acute viral gastroenteritis in all age groups in the United States. Approximately 3 million parents are forced to miss work, on average, 2.2 days, due to norovirus infections, to care for their children. The annual disease burden from norovirus in the U.S. alone is $10.6 billion. Globally, norovirus has become the leading cause of pediatric gastroenteritis in healthcare settings in countries that have adopted a rotavirus vaccine program.

Vaxart Oral Bivalent Norovirus Vaccine Dose

Dose: The vaccine was administered orally at three dose levels, with a prime and boost regimen 28 days apart. 

Vaxart Oral Bivalent Norovirus Vaccine Adverse Events

The Phase 2 dose-ranging study also demonstrated that the bivalent norovirus vaccine candidate was well tolerated, with a favorable safety profile that included no vaccine-related serious adverse events and no dose-limiting toxicity. The Phase 1b study found the vaccine was safe and well-tolerated in older adults. All solicited events were mild to moderate, with no grade 3 events related to the vaccine. Headache (14%) and malaise/fatigue (16%) were the most commonly solicited symptoms reported in the week following vaccine administration; headache (14%) and malaise/fatigue (14%) were reported at similar rates in the placebo group.

Vaxart Oral Bivalent Norovirus Vaccine News

March 6, 2025 - "A key finding of this study evaluating our first-generation oral pill norovirus vaccine candidate in elderly individuals was that the antibody and serum responses observed in these participants were robust and durable, and a cross-study analysis suggested that the observed antibody and cellular responses were independent of age. These findings are encouraging given that older adults have an increased risk of norovirus-related morbidity and may have less robust immune responses following vaccination than younger individuals," said James F. Cummings, MD, Chief Medical Officer at Vaxart. "Another key result was that an orally-administered vaccine can generate potent antibody responses in mucosal tissues outside the gastrointestinal tract, which could have important implications for use of our vaccine platform for norovirus and other indications."

April 30, 2024 - Dr. James F. Cummings, a Medical Officer, commented in a press release: "It can be difficult to immunize the youngest children mucosally because the immune system is still developing. Passive transfer of antibodies from mothers to infants via breast milk is potentially an innovative approach to improve infection resistance in infants."

December 21, 2023 - "This is an important step forward as we drive toward a vaccine candidate that may make it possible for mothers to protect their children against this highly contagious – and potentially lethal- virus. We look forward to announcing topline data from this study by the end of 2024," said Dr. James F. Cummings, Vaxart's Chief Medical Officer.

November 2, 2023: Dr. James F. Cummings, Vaxart's chief medical officer, comments, "We believe an oral norovirus vaccine pill may one day allow mothers to protect their infants against this highly contagious virus for which no approved vaccine is currently available."

September 6, 2023 - Challenge studies use higher quantities of virus than an individual may encounter during a naturally occurring infection. Yet, our vaccine candidate demonstrated a significant effect on infection and viral shedding, even though it did not achieve a statistically significant reduction in norovirus AGE," said Dr. James F. Cummings.

Vaxart Oral Bivalent Norovirus VXA-G1.1-NN Clinical Trials

A Phase 1, multicenter, randomized, double-blind, placebo-controlled, single-dose, dose-ranging study is designed to evaluate the safety, tolerability, and immunogenicity of an orally administered bivalent GI.1/GII.4 norovirus vaccine in healthy lactating females aged 18 years or older and their breast-feeding infants (aged 30 days to 11 months). The study is expected to enroll approximately 76 subjects at seven sites in South Africa. Subjects will be randomized into one of three groups: high-dose vaccine (N = 30), low-dose vaccine (N = 30), or placebo (N = 16).

This is a phase 2b randomized, double-masked, placebo-controlled vaccination and challenge study to assess the protective efficacy of the Vaxart Norovirus vaccine (VXA-G1.1-NN). Healthy adults will be randomized in a 1:1 ratio to receive one oral dose of vaccine or placebo.

Clinical Trial NCT03897309: Safety & Immunogenicity Study of Ad5 Based Oral Norovirus Vaccines (VXA-NVV-103)

Clinical Trial NCT02868073:  Phase 1 Placebo-controlled, Randomized Trial of an Adenoviral-vector Based Norovirus Vaccine (Completed)

Clinical Trial NCT03125473: Dose-Optimization Trial of VXA-G1.1-NN in Healthy Volunteers (Completed).

AADvac1 Alzheimer's Disease Vaccine

AADvac1 is a therapeutic vaccine candidate for Alzheimer's disease that targets misfolded tau protein, a common denominator of neurofibrillary pathology. The AADvac1 vaccine consists of a synthetic peptide derived from amino acids 294 to 305 of the tau sequence, i.e., KDNIKHVPGGGS, coupled to keyhole limpet hemocyanin; the precise molecular nature of the antigen has not been disclosed. In addition, AADvac1 uses aluminum hydroxide as an adjuvant.

The vaccine candidate showed several unique therapeutic features. It differs from other tau-based research by targeting the formation of pathological tau proteins and the spread of those already formed. AADvac1-induced antibodies discriminate between normal and pathological tau, ensuring only the latter are targeted. In this way, Axon's treatment is more effective and safer, says the company.

In September 2019, Axon Neuroscience published full results after a peer review (Novak et al., 2021). According to their reports, the treatment was safe and well-tolerated. Injection site reactions and transient confusion were the adverse events seen more often in the treated group compared to placebo. 

The Phase II trial ADAMANT study successfully met its primary objective, with AADvac1 shown to be safe and well-tolerated. The exceptional tau antibody response demonstrated by the vaccine is critical when treating the elderly. In addition,  AADvac1 significantly reduced the accumulation of Neurofilament Light Chain, an important biomarker of neurodegeneration, in the blood by 58% (p value=0.004). This was supported by substantially reduced core Alzheimer's disease cerebrospinal fluid biomarkers of tau pathology and tau neurodegeneration, including the most specific CSF biomarker, phosphotau–T217 (p value=0.009).

The company stated, 'AADvac1 is currently the most clinically-advanced tau therapy in development.' For details on AADvac1 clinical studies, see clinicaltrials.gov. AXON Neuroscience is a clinical-stage biotech company founded in 1999 with the world's largest team of researchers focused exclusively on tau-immunotherapies and tau diagnostic platforms.

AADvac1 Vaccine Indication

AADvac1 is indicated as an active immunotherapy vaccine candidate for patients with diagnosed Alzheimer's disease. It instructs the patient's immune system to produce specific antibodies targeting pathological tau. Tau proteins are vital in a brain's healthy, normal functioning. They are involved in various physiological processes, including cell signaling, the dynamics of the cellular cytoskeleton, and protecting DNA. Alzheimer's disease is triggered when these normal tau proteins become pathological by truncation, says the company.

AADvac1 Vaccine Dosage

Patients in the phase 2 study received up to 6 immunization doses.

AADvac1 Alzheimer's Disease Vaccine News

October 29, 2021 - Science Advances published the results of a study examining tau seed accumulation in Alzheimer's disease. The results suggest that from Braak stage III onward, local replication, rather than spreading between brain regions, is the primary process controlling the overall rate of tau accumulation in the neocortical areas. Furthermore, the number of seeds doubles only every five years. Thus, limiting local replication likely constitutes the most promising strategy to control tau accumulation during AD.

June 14, 2021 - Nature Aging published the results of ADAMANT, a 24-month double-blinded, parallel-arm, randomized phase 2 multicenter placebo-controlled trial of AADvac1, an active peptide vaccine designed to target pathological tau in AD.

April 3, 2020 - Vienna-based AXON Neuroscience SE presented the positive results of its Phase II trial for AADvac1, the first tau vaccine to treat and prevent Alzheimer's Disease AAT-AD/PD 2020 conference. AADvac1 exhibited a disease-modifying effect by significantly reducing the neurodegenerative process by 58% in comparison to the placebo arm (p value=0.004) as measured by Neurofilament Light Chain ("NfL") in the blood. NfL released in the blood and cerebrospinal fluid ("CSF") is a dynamic biomarker that reflects the extent of ongoing neurodegeneration in patients with Alzheimer's and other neurological disorders. The Phase II results indicate that AADvac1 prevents further neuronal damage in patients, maintaining levels similar to those typically observed in healthy elderly individuals. The most pronounced effects of the vaccine on clinical outcomes were observed among younger patients. In patients with young onset of Alzheimer's Disease, AADvac1 reduced the clinical decline measured by CDR-SB by 42% in comparison to the placebo arm (p value=0.062), MMSE (reduced by 31%), and ADCS-MCI-ADL (reduced by 26%). 2 Among the subgroup of younger-onset patients, the cognitive and functional effect was consistent with a significantly reduced rate of neuronal NfL accumulation in the blood by 73% in comparison to the placebo arm (p value=0.033), which represents double the effect observed in the study population as a whole.

Furthermore, MRI brain atrophy was considerably reduced in all individual brain areas associated with Alzheimer's Disease. The most substantial decrease of brain volume loss was observed in the cerebral cortex, by 47%, vs. the placebo arm (p value=0.021). This combination of clinical and biomarker outcomes demonstrates the disease-modifying effect of the AADvac1 therapy.

July 17, 2017 - AXON Neuroscience, a leader in tau research, took one further step, completing recruitment for its phase II clinical trial in Alzheimer's Disease. In total, 208 patients with mild AD were enrolled in the 24-month study, powered to evaluate the efficacy and safety of the AADvac1. With top-line data available in mid-2019, the "ADAMANT" phase II study is now the most advanced tau program in Alzheimer's research.

June 5, 2017 - AXON launches a 24-month Phase 1 Pilot Study of AADvac1 in Patients With Non-Fluent Primary Progressive Aphasia.

December 9, 2016 - The Lancet: Safety and immunogenicity of the tau vaccine AADvac1 in patients with Alzheimer's disease: a randomized, double-blind, placebo-controlled, phase 1 trial. AADvac1 had a favorable safety profile and excellent immunogenicity in this first-in-man study. However, further tests are needed to corroborate the safety assessment and to establish proof of the clinical efficacy of AADvac1.

AADvac1 Vaccine Clinical Trials

Clinical Trial NCT01850238: Safety Study of AADvac1, a Tau Peptide-KLH-Conjugate Active Vaccine to Treat Alzheimer's Disease (Completed)

AADvac1 is a candidate therapeutic vaccine for Alzheimer's disease that targets misfolded tau protein, a common denominator of neurofibrillary pathology. Based on preclinical results, the intervention is expected to reduce the number of neurofibrillary tangles, remove hyperphosphorylated tau protein, and reduce the oligomerized and insoluble pathological path tau in the brain, to halt the spread of neurofibrillary pathology through the brain, and thus prevent associated cognitive decline.

The vaccine's antigenic determinant is a synthetic peptide derived from a tau protein sequence coupled to keyhole limpet hemocyanin (KLH) and uses aluminum hydroxide (Alhydrogel) as an adjuvant. Presently, AADvac1 is intended as active immunotherapy for patients with diagnosed Alzheimer's disease (AD). Patients will receive 3 - 6 immunization doses; the raised titers of therapeutic antibodies and possible treatment benefits can extend beyond the study's duration. Because of the central role of pathological misfolded tau protein in AD's etiology, the vaccine is expected to be more effective than active or passive immunotherapies aiming to eliminate the amyloid β plaques that have been clinically investigated so far.

Clinical Trial NCT02031198: 18-month Safety Follow-up Study of AADvac1, an Active Tau Vaccine for Alzheimer's Disease (FUNDAMANT) (Completed)

AADvac1 is a candidate therapeutic vaccine for Alzheimer's disease that targets misfolded tau protein, a common denominator of neurofibrillary pathology. Based on preclinical results, the intervention is expected to reduce the number of neurofibrillary tangles, remove hyperphosphorylated tau protein, and reduce the oligomerized and insoluble pathological path tau in the brain, to halt the spread of neurofibrillary pathology through the brain, and thus prevent associated cognitive decline.

The vaccine's antigenic determinant is a synthetic peptide derived from a tau protein sequence coupled to keyhole limpet hemocyanin (KLH) and uses aluminum hydroxide (Alhydrogel) as an adjuvant. Presently, AADvac1 is intended as active immunotherapy for patients with diagnosed Alzheimer's disease (AD). However, according to need, patients will receive additional immunization doses beyond those administered in the preceding phase 1 trial; the raised titers of therapeutic antibodies and possible treatment benefits can extend beyond the study's duration.

Because of the central role of pathological misfolded tau protein in AD's etiology, the vaccine is expected to be more effective than active or passive immunotherapies aiming to eliminate the amyloid β plaques that have been clinically investigated so far.

Clinical Trial NCT02579252: 24 Months Safety and Efficacy Study of AADvac1 in Patients With Mild Alzheimer's Disease (ADAMANT) (Active). 

Alzheimer's disease (AD) is a chronic progressive neurodegenerative brain disorder. Throughout the disease, pathological proteins accumulate in the brain, damaging neurons and causing them to lose connections and die.

Currently, available treatments are designed to compensate for the neurotransmitter loss caused by the disease without affecting the disease process itself.

AADvac1 is designed to raise antibodies against pathological tau protein (the primary constituent of neurofibrillary pathology in AD). These antibodies are expected to prevent tau protein from aggregating, facilitate the removal of tau protein aggregates, and prevent the spreading of pathology, slowing or halting the disease's progress.

ACAM2000® Smallpox Mpox Vaccine Clinical Trials, Dosage, Indication, Side Effects

Emergent BioSolutions' ACAM2000 is a live, cell-cultured, replication-competent vaccinia virus vaccine, administered as a single dose, that protects individuals against mpox and smallpox diseases. ACAM2000 is derived from plaque purification cloning from Dryvax® and calf lymph vaccine, grown in African Green Monkey kidney (Vero) cells, and tested to be free of adventitious agents. The live attenuated vaccine does not contain variola and cannot cause mpox or smallpox. However, the ACAM2000 vaccine includes the vaccinia virus, which belongs to the poxvirus family, genus Orthopoxvirus, that can be transmitted from the vaccine recipient to unvaccinated persons with close contact with the inoculation site or exudate.

ACAM2000, a second-generation smallpox vaccine, replaced Dryvax, a first-generation vaccine derived from calf lymph. Dryvax and ACA2000  vaccines come from the New York City Board of Health strain of vaccinia. Approved by the U.S. FDA on May 2, 2007, ACAM2000 was licensed (STN: BL 125158). The FDA approved the supplemental Biologics License Application to expand the ACAM2000 indication for Mpox on August 29, 2024.

The U.S. Department of Health and Human Services awarded a contract to Emergent in September 2019, valued at approximately $2 billion over ten years, for the continued supply of ACAM2000 into the U.S. Strategic National Stockpile (SNS). The approval and availability of ACAM2000 in the SNS enhance the emergency preparedness of the USA against the use of smallpox as a dangerous biological weapon, says the FDA - Military Medications Guide (NSN): 6505-01-559-0815. On September 21, 2023, the New England Journal of Medicine (NEJM) published a Correspondence that concluded ACAM2000 vaccination prevented mpox disease in Military Personnel.

Emergent announced in August 2024 that it filed an Expression of Interest (EOI) with the World Health Organization (WHO) for the WHO's assessment of the ACAM2000® vaccine to be added as an Emergency Use Listing in connection with the May 2022 mpox outbreak. On May 27, 2022, the WHO published 'Vaccines and Immunization for mpox: Interim Guidance, as did the U.S. Centers for Disease Control and Prevention (CDC), which expanded access via Investigational New Drug Protocol, allowing the use of ACAM2000 for mpox prevention on June 30, 2022. In addition, the WHO and the CDC published updated Annexes to the Vaccines and immunization for Mpox, including ACAM2000.

On April 24, 2025, at the World Vaccine Congress in Washington, D.C., Emergent BioSolutions presented an overview of historical safety data (Prescribing Information and Medication Guide) for ACAM2000®.

Emergent BioSolutions (NYSE: EBS) is a global life sciences company based in Gaithersburg, Maryland. In 2017, Emergent acquired ACAM2000 from Sanofi Pasteur for about $125 million. Emergent BioSolutions confirmed in 2022 that ACAM2000 vaccine deliveries are expected to continue under the terms of the Company's existing contract with the U.S. HHS at unit volume levels ($225-$250) consistent with 2021 deliveries.

ACAM2000 Vaccine Mpox Indication 

U.S. Food and Drug Administration (FDA) approved the supplemental Biologics License Application for the expansion of the indication for ACAM2000® to include Mpox on August 29, 2024, for the prevention of mpox disease in individuals determined to be at high risk for mpox infection. In August 2024, two studies reported that previous smallpox vaccination with ACAM2000 was about 70% protective against mpox clade 2. On June 23, 2023, the U.S. CDC's Advisory Committee on Immunization Practices (ACIP) published updates on the mpox outbreak and vaccine efficacy, as well as a Morbidity and Mortality Weekly Report (MMWR) that presented mpox breakthrough cases in Chicago, IL. On May 18, 2023, the CDC COCA Call confirmed that the Chicago Department of Public Health reported one man vaccinated with ACAM2000 was reinfected with Mpox. A study published on April 25, 2023, found smallpox vaccines given until the mid-1970s offer cross-reactive immunity to mpox, researchers from Karolinska Institutet reported in a study published in the scientific journal Cell Host & Microbe. Public Health France updated on March 23, 2023, confirming that previously vaccinated individuals had been reinfected with Mpox.

ACAM2000 Vaccine Smallpox Indication

ACAM2000 is indicated for active immunization against smallpox disease for persons at high risk for smallpox infection. Smallpox vaccines are no longer routine in the U.S., although some soldiers and laboratory workers still are inoculated. ACAM2000 should not be given to people with Cardiac and Eye disease treated with topical steroids. People eligible for and offered ACAM2000 should be tested for HIV to ensure they are HIV negative, counseled on potential side effects, and given informed consent. The U.S. FDA published Questions about Smallpox and ACAM2000. Please read this Medication Guide before you receive vaccination with ACAM2000. This Guide does not replace consulting with your healthcare provider about ACAM2000 and smallpox disease.

A study published by The Lancet in November 2022 found substantial global spatial heterogeneity in the landscape of smallpox vaccination. Vaccination coverage is estimated to range from 7% to 60% in various countries.

ACAM2000 Vaccination Health Risks

ACAM200 vaccination warnings and precautions include myocarditis, pericarditis, encephalitis, encephalomyelitis, encephalopathy, progressive vaccinia, generalized vaccinia, severe vaccinial skin infections, erythema multiforme major (including Stevens-Johnson Syndrome), eczema vaccinatum resulting in permanent sequelae or death, accidental eye infection (ocular vaccinia), which can cause ocular complications that may lead to blindness, and fetal death. These may occur following primary or revaccination with live vaccinia virus vaccines, including ACAM2000®. These risks are increased in specific individuals and may result in severe disability, permanent neurological sequelae, and/or death.

Myopericarditis following smallpox vaccination is a known health risk for military forces. The incidence of confirmed myocarditis secondary to smallpox vaccination is estimated to be 16.1 per 100,000 service members. A recent U.S. Department of Defense study estimates that myocarditis may impact 12 service members per 100,000. Retrospective studies, which are confirmed by prospective studies, show that more than 10% of patients receiving the smallpox vaccine develop new-onset dyspnoea, chest pain, or palpitations. In addition, myocarditis can range from an influenza-like illness with subtle ECG changes to acute decompensated heart failure and death.

ACAM2000 Vaccine Side Effects

As of August 2024, the FDA labeling for ACAM2000® contains a contraindication for individuals with severe immunodeficiency. Severe localized or systemic infection with vaccinia (progressive vaccinia) may occur in persons with weakened immune systems. Individuals with severe immunodeficiency who are not expected to benefit from the vaccine should not receive ACAM2000®. The risk of experiencing severe vaccination complications must be weighed against the risk of experiencing a potentially severe or fatal smallpox or mpox infection.

A study published on August 26, 2021, concluded that electronic records surveillance of the entire vaccinated military population over ten years found rates of Myopericarditis, defined neurological events, and overall cardiac events consistent with those of prior passive surveillance studies involving Dryvax or ACAM2000 smallpox vaccines. The rate of adjudicated myocarditis among ACAM2000 recipients was 20.06/100,000 and was significantly higher for males (21.8/100,000) and for those < 40 years of age (21.1/100,000). Overall rates for cardiovascular events (Groups 1 and 2 combined) were 113.5/100,000 for the ACAM2000 vaccine. The rate of subjects with one or more defined neurological events was 1.91 (95% CI, 0.71-5.10).

Adverse events following ACAM2000 can be severe, including myopericarditis or Vaccinia virus transmission to household contacts. Additionally, the side effects of the ACAM2000 vaccine, also known as the smallpox vaccine, were discussed in a 2010 publication. Therefore, the vaccination site requires special care to prevent the virus from spreading - Updated Medication Guide. Once vaccinated, the virus remains on the skin's surface for approximately 30 days or until the vaccine site has healed. This means other people can contract the vaccinia virus and get infected. The vaccinia virus is NOT spread by coughing, sneezing, or sexual contact. 

ACAM2000 Vaccine Ingredients 

ACAM2000, developed by Acambis, is a second-generation lyophilized preparation of purified virus (grown in Vero cell line) in HEPES (hydroxyethyl piperazine ethanesulfonic acid)-buffered saline, pH 7.4, containing 1% to 4% human serum albumin USP, 5% mannitol, and trace amounts of antibiotics (100 U/mL polymyxin B and 100 µg/mL neomycin) (John Becher, RPh, CDC, personal communication, 2006). It must be reconstituted before the addition of a diluent.

ACAM2000 Vaccine Dosage

ACAM2000 is administered as a single-dose live virus preparation by the percutaneous route using the multiple puncture technique. ACAM2000 is administered differently from the typical "shot" associated with most vaccinations. A two-pronged stainless steel (or bifurcated) needle is dipped into the vaccine solution, and the skin is pricked several times in the upper arm with a droplet of the vaccine. The virus grows at the injection site, causing a localized infection or "pock" to form. A red, itchy, or sore spot at the vaccination site within 3-4 days indicates that the vaccination was successful, meaning an immune response has occurred. A blister develops at the vaccination site and then dries up, forming a scab that falls off in the third week, leaving a small scar. The vaccine stimulates a person's immune system to develop antibodies and cells in the blood and elsewhere that can help the body fight off an actual smallpox infection if exposure to smallpox ever occurs. Therefore, individuals who receive vaccination with ACAM2000 must take precautions to prevent the spread of the vaccine virus.

ACAM2000 is provided as a lyophilized preparation of purified live virus. After reconstitution, each vial of ACAM2000 vaccine contains approximately 100 doses (0.0025 mL/dose). The concentration of vaccinia virus is 1.0-5.0 × 10^8 plaque-forming units (PFU)/mL or 2.5-12.5 × 10^5 PFU/dose, as determined by plaque assay in Vero cells. In addition, the product contains 2% albumin USP and trace amounts of neomycin sulfate and polymyxin B sulfate.

ACAM2000 Vaccine Breast Milk

Breastfeeding is a contraindication for smallpox vaccination. The U.S. CDC recommends against breastfeeding in women until the risks associated with ACAM2000 vaccine exposure are evaluated. The CDC suggests temporarily withholding breastfeeding in the ten days following vaccination, during which the vaccine content is detectable in Breast Milk.

ACAM2000 Vaccine U.S. Government

The Company announced on September 9, 2025, that a contract modification had been executed for $56 million to supply ACAM2000® to the U.S. government. On November 6, 2024, company revenues from Smallpox Medical Countermeasures (MCM) products increased $108.0 million, or 437%, during Q3 2024, compared to Q3 2023. The increase was primarily due to the timing of USG purchases of ACAM2000® and VIGIV. On September 26, 2024, Emergent announced that it had secured approximately $400 million in orders for 2024 and 2025 associated with its vaccinia product portfolio, including ACAM2000 and CNJ-016. On May 30, 2023, Emergent BioSolutions announced a contract option has been secured to deliver ACAM2000® into the SNS. The option is the third of nine annual contract term extension options. It is valued at approximately $120 million and was awarded for a smaller volume than in prior years under a bilateral modification of the 10-year, roughly $2 billion contract Emergent signed with the Office of the Assistant Secretary for Preparedness and Response (ASPR) in the U.S. Department of Health and Human Services in 2019. The Army Smallpox Vaccinations Program provides insights into Package Inserts, Medication Guides, the DHA Trifold Brochure, Household contact information, and frequently asked questions and answers.

ACAM2000 Vaccine CPT Codes

The AMA-issued CPT code (90622) describes the ACAM2000 vaccine, manufactured by Sanofi Pasteur Biologics Co., for active immunization against smallpox disease in persons at high risk for smallpox infection. 

ACAM2000 Vaccine News

September 9, 2025 - The Company projected sales for ACAM2000® vaccine and ancillary products to exceed $120 million this year, driven by a diverse base of customers.

August 29, 2024 - "The FDA approval of ACAM2000® for immunization against mpox in high-risk individuals further strengthens and broadens our industry-leading smallpox portfolio, which includes VIGIV® and TEMBEXA®, said Joe Papa, president and CEO of Emergent.

August 19, 2024 - 50,000 doses of ACAM2000® will be donated to Direct Relief for potential deployment in Africa.

May 30, 2023 - "This option represents the importance the U.S. government places in preparing for the threat of smallpox," said Paul Williams, SVP and Products Business Head, Emergent BioSolutions. "It also highlights the value placed by the U.S. government in maintaining domestic manufacturing capabilities and the important role of public-private partnerships in addressing known and unknown public health threats."

September 14, 2022 - The U.S. CDC Research Letter - Volume 28, Number 11—November 2022: Mpox in Patient Immunized with ACAM2000 Smallpox Vaccine During 2022 Outbreak. We report a case of Mpox in the United States in a patient vaccinated with the ACAM2000 smallpox vaccine eight years earlier. Despite his vaccination status, he still contracted the disease. In addition, he showed prodromal symptoms preceding the development of painless penile lesions that later merged.'

June 30, 2022 - The U.S. CDC published 'Considerations for Mpox Vaccination: What You Need to Know.

September 3, 2019 - Emergent BioSolutions Awarded 10-Year HHS Contract to Deliver ACAM2000 Into the Strategic National Stockpile. Robert G. Kramer Sr., president and chief executive officer of Emergent BioSolutions, stated, "Emergent applauds the U.S. government's continued focus on national security demonstrated through its long-term stockpiling strategy, which ensures a sustainable supply of critical medical countermeasures such as ACAM2000 vaccine, and its investment in a stable domestic manufacturing infrastructure to help protect the U.S. population against smallpox in the event of an attack." 

June 21, 2019 - Emergent BioSolutions completes acquisition of ACAM2000® Business from Sanofi.

August 24, 2015 - U.S. FDA Risk Evaluation and Mitigation Strategy Release Letter - ACAM2000 - BLA 125158/58.

March 20, 2015 - PLOS One published - A peer-reviewed Prospective Study of the Incidence of Myocarditis/Pericarditis and New Onset Cardiac Symptoms following Smallpox Vaccination. Conclusions - Passive surveillance significantly underestimates the true incidence of myocarditis/pericarditis after smallpox immunization. Evidence of subclinical, transient cardiac muscle injury post-vaccinia immunization, with a rate 60 times higher than the incidence rate of overt clinical cases, requires further study to include long-term outcomes surveillance.

July 9, 2013 - Unintentional transfer of vaccinia virus associated with smallpox vaccines: ACAM2000 compared with Dryvax.

May 25, 20110 - ACAM2000™: The new smallpox vaccine for the United States Strategic National Stockpile.

April 17, 2008 - ACAM2000 is a newly licensed cell culture-based live vaccinia smallpox vaccine. Studies with ACAM2000 indicate that it closely matches the safety of Dryvax in both non-clinical and clinical trials. ACAM2000 met two of the four primary surrogate efficacy endpoint criteria for the Phase III clinical trials. Concerns exist regarding the incidence of Myopericarditis Associated with ACAM2000 and Dryvax. However, so far, the cardiac events seem to be self-limited.

ACAM2000 Clinical Trials

ACAM2000 Smallpox vaccine has been involved in various clinical trials.

Pediarix Vaccine Description - 2022

GSK's Pediarix multi-vaccine contains diphtheria and tetanus toxoids and acellular pertussis adsorbed, hepatitis B (recombinant), and inactivated poliovirus vaccine, approved by the U.S. FDA in 2002.

STN: BL 103907; CPT Code: 90723

Pediarix Indication

Pediarix is a vaccine for active immunization against diphtheria, tetanus, pertussis, and infection caused by all known subtypes of hepatitis B virus and poliomyelitis. 

Severe allergic reaction (e.g., anaphylaxis) after a previous dose of any diphtheria toxoid-, tetanus toxoid-, pertussis-, hepatitis B-, or poliovirus-containing vaccine, or to any component of PEDIARIX. Encephalopathy within 7 days of administration of a previous pertussis-containing vaccine. Progressive neurologic disorders. In clinical trials, PEDIARIX was associated with higher rates of fever relative to separately administered vaccines.

Pediarix Dosage

Pediarix is approved for use as a three-dose series in infants born of hepatitis B surface antigen (HBsAg)-negative mothers. 

Pediarix may be given as early as 6 weeks of age through 6 years of age (before the 7th birthday). Three doses (0.5-mL each) by intramuscular injection at 2, 4, and 6 months of age.

Pediarix News 2019 - 2022

August 1, 2022 - CDC says findings in the New York wastewater indicate others may be shedding the poliovirus as officials urge residents to ensure they are vaccinated.

February 9, 2022 - GSK reported Infanrix/Pediarix sales decreased 14% AER, 9% CER to £543 million, reflecting lower tender volume in Europe and International as well as a change in recommendation for the dosing schedule in Germany.

July 28, 2021 - GSK announced 'Sales of DTPa-containing vaccines (Infanrix, Pediarix, and Boostrix) grew by 45% AER, 55% CER. Infanrix/Pediarix sales rose 14% AER, 24% CER to £136 million, reflecting increased channel stock replenishment on wholesaler purchasing patterns and demand in the US, partly offset by a change in recommendation for the dosing schedule in Germany and supply constraints in Europe. Boostrix sales grew 92% AER and more than 100% CER to £146 million, largely driven by higher demand in the US and internationally.

December 31, 2020 - According to Reuters, for the new year, GSK plans to hike prices on two of their vaccines, Shingrix and Pediarix.  These price increases are a direct result of the COVID-19 pandemic and the reduced number of doctor visits, thus reducing the number of vaccinations given.

June 2, 2020 - COVID-19 Impact on Global Human Vaccines Market Size, Shares, Trends, Demands, Types, Applications & Key Industry Players - Sanofi Pasteur, Merck, Pfizer, AstraZeneca, Valneva, GSK, Seqirus.

September 17, 2019 - Merck HepB vaccine shortage extended through mid-2020.

Pediarix Clinical Trials

GSK's Pediarix has been in many studies to test immunogenicity, safety, and reactogenicity.