COVID-19 vaccine maker Moderna will make a third booster shot for its two-dose vaccine available to Americans by the fall, CEO Stéphane Bancel said this week.
Moderna’s vaccine is more than 90% effective against the coronavirus six months after the second shot, studies show. What remains unclear is how long the immunity to the virus lasts.
The same is true for Pfizer’s two-dose COVID-19 vaccine.
“A third dose will likely be needed somewhere between six and 12 months. And from there there will be an annual revaccination. But all of that needs to be confirmed,” Pfizer CEO Albert Bourla said Thursday at a virtual event hosted by CVS Health .
A third booster shot against the virus is not yet required, but health experts say it could provide additional immunity against COVID-19 variants starting to spread to the US from Brazil, South Africa and the UK.
“They all have a suspicion that they can evade the protections the vaccines provide,” Justin Gill, an emergency care nurse specialist, told CBSN.
There is also a chance that fully vaccinated individuals may still become infected with the virus, as none of the available vaccines offers 100% immunity against COVID-19.
“We know some [who are fully vaccinated] are still infected and test positive for COVID-19, but there are still many unknowns about those individuals who end up testing positive, ”said Gill.
Such “breakthrough” infections are considered very rare, but can occur when vaccinated individuals are exposed to variants or significant viral load.
While drug manufacturers develop a booster shot, individuals who have already received two doses of the Moderna or Pfizer vaccine can be confident that they are well protected against COVID-19.
“Ultimately, it still offers great protection,” said Gill. “But we know that some are still getting the COVID-19 virus, and it’s essential that they still follow those public health guidelines, wear a mask, and remain vigilant when around other individuals.”
According to the Kaiser Family Foundation, confidence in vaccines among individuals in the US has risen as more Americans have seen their friends and relatives vaccinated.
According to the Centers for Disease Control and Prevention, to date, about 38% of the U.S. population has received at least one dose of the vaccine and 24% has been fully vaccinated.