The US government announced on Wednesday (18) that it will start applying a third dose of the Covid vaccine from September 20, as studies show vaccine protection tends to lose strength over months.
The determination is that the booster is taken eight months after the person has completed the immunization with two doses. The measure will initially target those who have taken the Moderna and Pfizer vaccines.
A new application for those who took Janssen’s immunizing agent, in a single dose, should also be made, but it is still under study, as it started to be applied after others, in March, and research into its long-term effectiveness is still ongoing. In progress.
The first people to be vaccinated again will be the elderly living in retirement homes and health workers. Then, the other elderly people, in a staggered way by age group.
The recommendation is that Americans who are already immune do not rush to take the third dose, but wait eight months after taking the second dose.
In announcing the measure, authorities said they wanted to stay ahead of the virus and reduce the risk of another outbreak of the disease. The decision was based on studies that show that the effectiveness of mRNA vaccines, such as Moderna and Pfizer, waned over months and with the arrival of the delta variant. Detailed reports will be published on the CDC (Center for Disease Control) website.
“Antibody levels decline over time, and higher antibody levels may be needed to protect against the delta variant,” said Anthony Fauci, director of the National Institute of Infectious Diseases and adviser to President Joe Biden. It is estimated that the third dose could increase the number of antibodies against Covid tenfold.
Some studies have shown that a few months after the second dose of any vaccine, the amount of antibodies tends to drop. Despite this, people who are immune are still less likely to have severe cases of Covid than those who are not immune. In the United States, 99% of deaths have occurred in people who have not been vaccinated.
“The Covid-19 vaccines authorized in the United States continue to be remarkably effective in reducing the risk of severe cases, hospitalizations and death, even against the delta variant,” said Jeff Zients, White House coordinator for fight against Covid.
The debate over the third dose in the United States comes amid another peak in Covid cases in August. The average number of daily cases is around 140,000, a number that has not been reached since February. At the worst time of the crisis in the country, in January, there were more than 250,000 cases per day. The total number of deaths is at a lower level. The current average is 696 deaths per day, double the level of three weeks ago, but still far from the 3,000 at the height of the crisis.
Schools and universities are back to school and the weather starts to cool from September, two factors that could facilitate the spread of the Covid.
In the United States, there are many vaccines available. Of the 417.4 million doses delivered, only 357.8 million have been applied to date. Vaccination in the country is free and available at drugstores, supermarkets and temporary outlets, but it has progressed more slowly in recent months, amid Americans’ lack of interest in doses.
Vaccination in the country is accessible to everyone from the age of 12. As of Tuesday (17), 59.9% of the total population had received at least one injection and 50.9% were fully vaccinated.
In an attempt to advance the application of vaccines, the Biden government and some states have exerted pressure and stimuli for public officials to be vaccinated. Some cities, such as New York and San Francisco, have started requiring proof of vaccination to access recreation areas, while other states, such as Florida and Texas, have created laws that prevent establishments from applying for a. proof of vaccination.
The WHO (World Health Organization) is against the application of booster doses while regular vaccination is slow in many countries of the world and calls for additional vaccines to be targeted on the poorest countries.
Most African countries did not even vaccinate 5% of the population with the first dose. Haiti, in the Caribbean, only started the coronavirus vaccination campaign last month.
The US government has said it will continue to donate vaccines to other countries because it believes tackling the pandemic depends on a global solution.
Other countries are also making progress with plans to boost immunization. Israel has been distributing the third dose to people over 50 since July. Last week, Chile started applying an additional dose of the AstraZeneca vaccine to older people who had already received two doses of Coronavac. And Uruguay has approved a booster dose of the Pfizer vaccine for those who have already received two injections of Coronavac.
Currently, Brazil is conducting studies to evaluate the benefits of a booster dose with vaccines from Pfizer, Oxford / Astrazeneca and Coronavac.