COVID-19 boosters: What you need to know

As the virus evolves and new variants emerge, will the world need booster vaccines to get ahead of COVID?

An elderly woman receives a booster shot of her vaccination against the coronavirus disease (COVID-19) at an assisted living facility, in Netanya, Israel. [File: Ronen Zvulun/Reuters]

Will the world need COVID-19 vaccine booster jabs? Even as most nations struggle to administer a first round of doses to protect their populations, evidence is emerging that booster shots may eventually be necessary.

Top United States officials say it is too early to call for boosters, but vaccine maker Pfizer is pushing for government approval and Israel announced it will offer booster jabs to at-risk people who already had the vaccine.

Here is what is driving the debate:

The rise of the Delta variant

First detected in India and now the dominant form of new coronavirus infections in many countries, the Delta variant of the coronavirus has raised doubts whether presently available vaccines offer enough protection.

A booster shot would be warranted if there is a substantial increase in hospitalizations or deaths among vaccinated people, experts say. So far in the US, the overwhelming majority of severe illness is among unvaccinated people.

Israel study shows protection wanes

Israel’s Health Ministry announced on July 5 that the Pfizer-BioNTech vaccine was only 64 percent effective at preventing transmission and disease from the Delta variant, a reduction from 95 percent effectiveness in May.

The Israeli Health Ministry said its data, which was not published, showed that protection had waned in individuals who got the vaccine in January or February. On July 11, the Israeli government said it would offer a booster to adults with weak immune systems.

Indicative of the dilemma governments face, the Palestinian Authority is still struggling to administer a first round of vaccines to Palestinians in the occupied territories, while the Israeli government has refused to share its supply of vaccines.

Dr Fauci says ‘too soon’

Dr Anthony Fauci, the US’s top infectious disease scientist, said on July 11 it was too soon for the US government to recommend another shot but he would not rule out the possibility booster shots would be necessary in future.

“Right now, given the data and the information we have, we do not need to give people a third shot,” he said. “That doesn’t mean we stop there … There are studies being done now, ongoing as we speak, about looking at the feasibility about, if and when we should be boosting people.”

However, Dr David Kessler, the Biden administration’s chief science officer, told the US Congress back in April booster shots might be needed within a year.

Antibodies jump five-to-10 times

Early data from a Pfizer booster study suggests people’s antibody levels jump five-to-10 times after a third dose, compared with their second dose months earlier.

US government officials at the Centers for Disease Control and Prevention and the FDA pushed back against Pfizer’s claims saying that they did not view booster shots as necessary “at this time”.

Pfizer to seek US, EU regulatory approvals

Pfizer and German partner BioNTech said last week that they will ask US and European regulators within weeks to authorize a booster dose due to an increased risk of infection after six months.

The companies did not share the data showing that risk, but said it would soon be made public. A meeting with federal health officials to discuss the matter was scheduled for Monday, Pfizer said.

Leading experts question the need

Leading vaccine experts questioned Pfizer’s rationale and said that more data was needed to justify a booster, especially as many nations still struggle to administer initial doses.

“It’s disappointing that with such a complicated decision they took such a unilateral approach,” Dr Larry Corey, a virologist at Seattle’s Fred Hutchinson Cancer Center who is overseeing US COVID-19 vaccine trials, told the Reuters news agency.

Source: Al Jazeera and news agencies