As the fourth COVID-19 vaccine dose has started to roll out in more countries, doubts remain on whether or not the extra jab would be necessary. Experts are torn, with the World Health Organization still skeptical about its recommendation.

Extended Protection

The fourth dose is intended to extend the protection the COVID-19 vaccines provide. The U.S. Food and Drug Administration (FDA) has already authorized it for people aged 50 and above and the immunocompromised. But many have been wondering if the fourth dose will also be rolled out to the general public.

Last October, the Centers for Disease Control and Protection (CDC) issued new guidance on how the elderly and immunocompromised should stay protected amid the ongoing pandemic. The public health agency cited vaccine efficacy data in various studies to back its fourth dose recommendation.

Though the CDC recommended the fourth dose for people 50 and older, it did not give the go signal for it to be administered in healthy adults in the absence of a more solid health strategy amid the emergence of newer SARS-CoV-2 variants and whatnot.

Casting Doubt

A study from Israel published last month reported that even though a fourth dose of the Pfizer vaccine can offer protection against severe COVID-19, it is not enough to last long-term. The team found that the shot protected against serious illness for at least six weeks and against infection for at least four weeks.

Since there is no clear evidence of the efficacy of the fourth dose, the World Health Organization (WHO) has been hesitant to endorse it. WHO chief scientist Soumya Swaminathan even told CNBC “there isn’t any good evidence at this point of time” that the additional booster will be beneficial.

“What we know from immunology is that if you give another booster, you will see a temporary increase in the neutralizing antibodies. But what we’ve also seen is that these neutralizing antibodies will wane quite rapidly,” Swaminathan added.

University of Alabama professor of medicine Paul Goepfert expressed a similar sentiment when he told the outlet, “A fourth dose doesn’t really do much of anything ... I’m not sure we need to get out and just jump up and down screaming that everybody needs to get aboard.”

Annual Boosters

The idea of giving the fourth dose to everyone opens the doors to the possibility of having annual booster shots. White House chief medical advisor Anthony Fauci alluded to this back in January when he said that people might need to get boosters every year or two as the pandemic continues.

Geopfert agreed to this, saying “only time will tell” for how long will people need to take boosters against SARS-CoV-2 infection. But for now, the way he sees things, the best approach is to have a booster “every year” to stay protected against COVID-19.