Today, Uruguayans vaccinated with Coronavac can receive a Pfizer booster dose

RIO DE JANEIRO, BRAZIL – With the Covid 19 epidemic seemingly under control, Uruguay will receive a booster dose from Pfizer starting today for those vaccinated with Coronavac, a combination that has no studies but is considered safe and necessary by local experts given the threat of the Delta variant.

About one-third of Uruguay’s 3.5 million residents have already signed up to be vaccinated with the U.S. vaccine after receiving two vaccine injections from the Chinese laboratory Sinovac.

Read also: Check out our coverage on Uruguay

The country has vaccinated 73% of its population with at least one dose of Covid-19, while 67% are fully vaccinated.

However, of those vaccinated, 65% received Coronavac, which is considered less effective in reducing infections.

In this context, by approving the booster, the authorities want to take advantage of the fact that there is no community circulation of Delta to build an immunological barrier.

In doing so, the Uruguayan government is ignoring the World Health Organization (WHO), which a few days ago called for nations to postpone plans to administer a third dose until countries with vaccination backlogs have vaccinated at least 10 percent of their populations.

“Negative, central,” Public Health Minister Daniel Salinas responded when asked about the issue. “The results are there, the recommendations are there, the vaccines are there.”

THIRD COUNTRY

Uruguay is the third country in Latin America, after Chile and the Dominican Republic, to boost an inactivated virus vaccine (Sinovac) with a dose of messenger RNA type (Pfizer).

However, there are no studies on the combination of these two platforms.

The government of Luis Lacalle Pou made this decision on the recommendation of the National Advisory Commission on Vaccines and an ad hoc group. At the same time, the scientific community never tires of repeating that the combination is safe.

“Mixing the platforms strengthens immunity. In the past, this has always been the case,” virologist Santiago Mirazo told AFP. “From a theoretical and experimental point of view, this is clear throughout the history of immunology,” he added.

The scientist recalls that one of the reasons for this decision is the finding that Coronavac antibody titers decrease over the months.

Are there risks? For Mirazo, there are no more than those that any vaccine potentially faces on its own.

“The studies that have been done on combination vaccines have shown very little increase in side effects,” he says, adding that they are usually “mild and moderate.”

According to a study by the Uruguayan Ministry of Health, the percentage of adverse effects reportedly attributable to vaccination was 0.02% for Coronavac and 0.06% for Pfizer in doses administered through July 15.

The most common were injection site pain, headache, muscle aches, malaise, diarrhea, tremors, headache, putrefaction, and bronchial spasms.

For serious effects, mostly venous thrombosis, the ratio was two per million doses.

“The measure is reasonable, wise, timely, and evidence-based,” Mirazo emphasizes. “It is a public health decision.”