Vaccine News

A multijurisdictional measles outbreak is ongoing in Canada and the United States in 2025.

Although measles was eliminated in Canada in 1998, an average of 91 cases, many travel-related, were reported annually.

According to the Canadian Government's data release on May 2, 2025, the current outbreak began in New Brunswick in October 2024 and has continued to spread in Alberta, Manitoba, Ontario, Prince Edward Island, and Quebec.

The data revealed 970 measles cases had been reported in Ontario, out of the 1,177 total cases in Canada. Of the virus genotypes analyzed, D8 was dominant.

During Ontario's outbreak, 451 measles cases have been confirmed in Ontario's Southwestern Public Health, including the City of St. Thomas, Elgin County, and Oxford County.

Data from Toronto, a city with over 2.7 million people, has confirmed only three cases.

These data indicate that Ontario's measles outbreak is primarily a rural, not urban, concern.

As of May 1, 2025, the Centers for Disease Control and Prevention (CDC) reported 935 confirmed measles cases in 30 U.S. jurisdictions, with Texas the leader.

Measles is an exceptionally infectious virus but can be easily prevented with an effective vaccine.

A study published by The Lancet in May 2025 supports using the MR vaccine at six months to protect young infants during measles outbreaks and in settings with increased risk or high transmission.

The CDC recommends evaluating your family's need for early vaccine doses before international travel. After you return, monitor your health for three weeks and call your healthcare provider if you or your child gets sick with a rash and fever.

The UK Health Security Agency (UKHSA) recently reviewed its guidance for countries at risk of dengue fever outbreaks. Last year, records of dengue outbreaks and related fatalities were set in many countries.

As of May 2, 2025, based on this review, most countries with a known risk of dengue now have a vaccine recommendation for some travellers.

However, the following countries have sporadic local dengue cases, but a vaccine is not recommended: Australia, Croatia, France, Italy, Madeira, Spain, the United Arab Emirates, and the United States.

In the U.S., locally acquired dengue was reported in 2025 in areas such as Miami-Dade County in Florida.

According to the UKHSA, health professionals should consider the possibility of dengue in all returned UK travellers with a fever or flu-like illness who have recently visited dengue risk regions. Suspected dengue patients should discuss this matter with their local microbiology, virology, or infectious diseases consultant, giving a full travel/clinical history. 

The live, attenuated dengue vaccine called Qdenga® is licensed in the UK, but is unsuitable for all travellers.

Qdenga is currently not licensed in the U.S.

The UKHSA and NaTHNaC dengue recommendations are based on published data focusing on evidence of local mosquito-borne dengue transmission from January 2020 to December 2024.

Despite the significant drop in recent dengue cases, the President of the Republic of the Philippines, Ferdinand R. Marcos Jr., today ordered the Department of Health (DOH) to closely monitor the outbreak situation as part of its continued efforts to safeguard the health of Filipinos.

In a media release on May 2, 2025, Presidential Communications Undersecretary and Palace Press Officer Claire Castro attributed the significant decrease in new dengue cases to the prompt response of the DOH under its "Alas Kwatro Kontra Mosquito" campaign.

Castro said that from 12,050 recorded dengue cases during March 2 to 15, the figure dropped to 9,289 from March 16 to 29, 2025.

While this decreasing trend is a positive indication, the DOH reported that about 95,000 dengue cases have been recorded since the beginning of 2025. This data represents a 75% increase compared to last year.

The DOH noted the low case fatality rate of 0.36 percent, or about four deaths per 1,000 dengue cases, in 2025.

Previously, the Quezon City Government's City Health Department declared a dengue outbreak.

The DOH's "Alas Kwatro Kontra Mosquito "campaign involves "Taob, Taktak, Tuyo, Takip" as the four basic ways of cleaning and eliminating possible mosquito breeding grounds.

Castro said the government's campaign encourages families, schools, and workplaces to clean potential mosquito breeding grounds daily at 4:00 PM. She echoed the DOH's call for the public to maintain cleanliness and prepare for the onset of the rainy season.

Throughout 2025, a second-generation dengue vaccine has been offered in various countries in the Asia-Pacific Region as a disease prevention option. Unfortunately, the QDENGA vaccine is not available in the United States.

To alert international travelers of this health risk, the U.S. CDC's Global Dengue Advisory included the Philippines, advising travelers to risk areas to prevent mosquito bites.

Health authorities in the Democratic Republic of the Congo (DRC) recently announced they are intensifying their response to an anthrax outbreak in North Kivu province.

The anthrax outbreak's epicenter is located in four health zones around Lake Edward on the border between the DRC and the Republic of Uganda. It is linked to the ongoing one in Uganda, where seven suspected human cases have been reported in the western Kabale district.

According to a statement from the World Health Organization (WHO) on May 1, 2025, there were 16 suspected cases, one confirmed case, and one related fatality this year.

The WHO states that people can get the disease directly or indirectly from infected animals or exposure to infected or contaminated animal products. Anthrax in humans is not generally regarded as contagious, but human cases of anthrax require hospitalization or treatment with antibiotics.

While human vaccines are in limited supply and used primarily for the protection of selected individuals with possible occupational exposure to anthrax, such as government employees.

The U.S. Centers for Disease Control and Prevention published Guidelines for the Prevention and Treatment of Anthrax, which outline preferred prevention and treatment regimens for naturally occurring anthrax.

In the United States, access to anthrax vaccines, such as CYFENDUS™, is controlled by the government. 

The first instance of determining the acceptability and feasibility of incorporating the Tropis needle-free jet injector for intradermal administration of fractional dose poliovirus vaccine (fIPV) produced very positive results.

PharmaJet® today announced the publication of a study demonstrating the benefits of the PharmaJet Tropis needle-free system compared with needle and syringe (N/S) for intradermal administration of fIPV.

Tropis was preferred over N/S by significant margins by both parents (98%) and nurses (98.5%) in Cuba.

Survey respondents cited ease of vaccination, diminished crying, and increased comfort as the benefits of Tropis. Of note, seroprevalence did not differ significantly between Tropis and N/S.

The results indicated significantly fewer adverse events with Tropis (6%) compared to N/S (13%) (p = 0.028).

Paul LaBarre, Vice President of Global Business Development, PharmaJet, commented in a press release on May 1, 2025, “The strong performance of Tropis ID delivery is consistent with results recently seen in WHO-sponsored polio campaigns in Pakistan, Nigeria, and Somalia where Tropis has been used to administer polio vaccinations to nearly 12 million children.”

The study, entitled "Tropis needle-free injector for fractional-dose IPV administration: A pilot study for integration into routine immunization services in Cuba," is published in the journal Vaccine on April 11, 2025.

This was a community-based feasibility survey and poliovirus antibody seroprevalence assay conducted in Camagüey and Ciego de Ávila provinces, Cuba, in 2019–2020 as part of a research collaboration between the Instituto Pedro Kourí in Havana, Cuba, and the World Health Organization. 

According to various media reports today, the U.S. government is modifying the method for authorizing or approving vaccines for human use.

“All new vaccines will undergo safety testing in placebo-controlled trials prior to licensure,” a U.S. HHS spokesperson told The Washington Post in response to an inquiry about HHS Secretary Robert F. Kennedy Jr.’s comments on the measles vaccine and general vaccine policy.

HHS did not clarify which vaccines this new policy would apply to, according to the Post on April 30, 2025.

The government's Clinical Trials website defines placebo-controlled trials as studies using an inactive substance or treatment that appears the same as, and is administered in the same manner as, an active drug or intervention being studied. The placebo comparator arm of the study is a group of participants who receive a placebo during a clinical trial.

With over 100 countries reporting Dengue fever cases this year, several governments in the Pacific Region are missing alerts for this mosquito-transmitted disease. 

For example, the Government of Samoa's Ministry of Health has officially declared a Dengue outbreak in 2025. There has been a significant increase in the number of dengue cases, particularly in Upolu, over the past two weeks.

As of April 17, 2025, the Ministry has reported 15 Fengue cases and one reported death this year.

Samoa has issued a red alert for Dengue of undetermined serotype.

The Ministry of Health is actively monitoring the situation, strengthening response efforts, urging the public to take preventive measures against mosquito bites and to seek medical attention if symptoms appear.

On April 15, 2025, the U.S. CDC reissued a Level 1 Global Dengue Advisory, which identified several countries in the Pacific Region. The CDC recommends avoiding mosquito bites as a way to prevent Dengue infection.

Additionally, several countries in the Pacific Region offer access to Dengue vaccination services in 2025.