If you've already had two doses of either the Pfizer/BioNTech Covid-19 or Moderna vaccine-- is it already time for a third dose?
Yes, say the vaccine makers, citing data showing the vaccine wearing off after six months.
They say a third shot is needed as early as six months after the second, implying the initial regimen -- in their view -- isn't effective enough for very long. They are seeking approval to market the number three booster.
Causes for concern raising the possible need include: the fact that Israel has found Pfizer vaccine's effectiveness appears to be wearing off. Vaccine effectiveness there is down to a reported 64% protection. Also, the vaccine is proving largely ineffective against a dominant variant of Covid-19, "Delta." Additionally, Pfizer is also working to develop a separate vaccine that works better against the variant.
The development of variants were expected and anticipated from the start, according to virologists. But officials had hoped the vaccines would prove highly effective against all versions of Covid-19 as the virus goes through natural modifications and changes.
"As seen in real world data released from the Israel Ministry of Health, vaccine efficacy in preventing both infection and symptomatic disease has declined six months post-vaccination, although efficacy in preventing serious illnesses remains high," Pfizer said.
However, the FDA and Centers for Disease Control (CDC) say here isn't yet a demonstrated need for yet another shot.
"Americans who have been fully vaccinated do not need a booster shot at this time," said the agencies in a joint statement.
The Covid-19 vaccines are under study for possible side effects at the same time they are already in use. They haven't yet been on the market a full year. The government approved them using an emergency authorization that allowed them to skip or collapse steps in the normal testing and approval process.
So far, warnings and cautions have emerged about vaccine links to numerous injuries and deaths including from heart inflammation (particularly in young men and boys), blood clots and other blood issues, and a variety of neurological and other adverse events.
However, public health officials are recommending widespread use of the vaccines, even among the young who are said to be at a near "zero" statistical risk of serious illness, saying the vaccines are safe and effective.
Scientists who are critical of the government's Covid-19 vaccine strategy point out that unlike those who have been vaccinated, people who were infected with Covid-19, or fought it off naturally without symptoms (which is the majority, according to scientists), are proving to be largely immune from the variants. Almost everybody who gets Covid-19 recovers without serious illness, according to scientists.
For people with no symptoms, there's no way to know for sure whether they fought off Covid-19 naturally, because they may not have needed to develop antibodies at all; or the antibodies they developed may not be present at measurable levels during subsequent tests.
Americans who have been fully vaccinated do not need a booster shot at this time. FDA, CDC, and NIH are engaged in a science-based, rigorous process to consider whether or when a booster might be necessary. This process takes into account laboratory data, clinical trial data, and cohort data – which can include data from specific pharmaceutical companies, but does not rely on those data exclusively.Joint CDC and FDA statement
Read the full CDC and FDA statement below.
Joint CDC and FDA Statement on Vaccine Boosters
The United States is fortunate to have highly effective vaccines that are widely available for those aged 12 and up. People who are fully vaccinated are protected from severe disease and death, including from the variants currently circulating in the country such as Delta. People who are not vaccinated remain at risk. Virtually all COVID-19 hospitalizations and deaths are among those who are unvaccinated. We encourage Americans who have not yet been vaccinated to get vaccinated as soon as possible to protect themselves and their community.
Americans who have been fully vaccinated do not need a booster shot at this time. FDA, CDC, and NIH are engaged in a science-based, rigorous process to consider whether or when a booster might be necessary. This process takes into account laboratory data, clinical trial data, and cohort data – which can include data from specific pharmaceutical companies, but does not rely on those data exclusively. We continue to review any new data as it becomes available and will keep the public informed. We are prepared for booster doses if and when the science demonstrates that they are needed.