Pfizer-BioNTech effective at one dose, longer dose intervals for Oxford-AstraZeneca, 6 million undelivered dose backlog because of winter storms and other COVID-19 vaccine news this week

February 20, 2021
Peter Wehrwein

Evidence of greater efficacy for a longer dosing interval for the Oxford-AstraZeneca vaccine

The Oxford-AstraZeneca vaccine is more effective if the doses are given 12 weeks apart, according to findings reported in Lancet on Friday (Feb. 19).

Oxford University researchers said that based on data amassed from four studies, the efficacy of the vaccine was 81.3% among those who received the doses 12 weeks apart or longer. Among those who received the doses at an interval of six weeks or less, the efficacy was 55.1%.

“A 3-month dose interval might have advantages over a program with a shorter dose interval for roll-out of a pandemic vaccine to protect the largest number of individuals in the population as early as possible when supplies are scarce while also improving protection after receiving a second dose,” they wrote in the interpretation section of the abstract

The researchers had already reported their findings in a preprint several weeks ago, so the dose interval data wasn’t new news, but publication Lancet lends it credibility.

Evidence from Israel that one shot of Pfizer-BioNTech vaccine may be enough

Results of a study of 9,109 healthcare workers at Israel’s largest hospital showed that the two-dose Pfizer-BioNTech vaccine is 47% effective in days 1-14 after the first inoculation and 85% effective in days 15-28. At the full two doses, the Pfizer-BioNTech is 95% effective so a 10-percentage point decrement might be manageable if it means a one-and-done vaccine schedule.

The results, which were published online in Lancet on Thursday (Feb. 18) are from an observational study so all the usual, interpret-with-care caveats apply.

Meanwhile, Pfizer is asking the FDA to reconsider the required storage temperature for the Pfizer-BioNTech vaccine. Currently, the vaccine must be stored at between minus 80 degrees Celsius and minus 60 (minus 112 degrees Fahrenheit and minus 76). But Pfizer says it has data that show the vaccine is stable when stored at minus 20 degrees Celsius (minus 4 degrees Fahrenheit).

Evidence that the Pfizer-BioNTech vaccine may be less protective against the South African variant

Evidence is accruing that the current crop of vaccines may be less effective against the South African variant of SARS-CoV-2 than other strains. On Wednesday (Feb. 17), another piece of evidence was added to the pile.

A team of Pfizer, BioNTech and University of Texas Medical Branch researchers reported results in the New England Journal of Medicine that show the Pfizer-BioNTech elicited a weaker antibody response — weaker by two-thirds — to the South African virus than it does other variants.

The lower antibody response doesn’t necessarily mean the vaccine won’t work against the South African virus; antibodies are just one aspect of the immune response that a vaccine can help prime. Also, the RNA vaccines lend themselves to modifications that would make them protective against variants.

Backlog of 6 million undelivered doses because of winter storms

The winter storms that hit Texas, Louisiana and other states this week resulted in a backlog of 6 million undelivered vaccine doses, said Andy Slavitt, the senior adviser to the White House White House COVID-19 Response Team, during a briefing on Friday (Feb. 19).

Slavitt said bad winter weather had affected the distribution by Fedex, UPS, and McKesson and closed down 2,000 vaccine sites because of power outages. The undelivered vaccines have been “sitting, safe and sound in our factories and hubs,” he said.

“Now as weather conditions improve we are already working to clear this backlog. 1.4 millions doses are in transit today (Feb. 19) and we are anticipating all the backlogged doses will be delivered within the next week,” Slavitt said at the briefing.

A third of troops are turning down the jab

About one-third of U.S. troops are refusing to get a COVID-19 vaccine, a top Pentagon official said in testimony Wednesday (Feb. 17).

"Acceptance rates are somewhere in the two-thirds territory and, of course, it varies by different groups," Air Force Maj. Gen. Jeff Taliaferro, the Joint Staff's vice director for operations, told the committee.

The vaccine is not mandatory. “Of course the vaccine is the right to do, it is clearly safe for our service members and we need to educate our faces to help them understand the benefits,” Taliaferro said.

U.S., other rich countries pledge $4.3 billion toward poor country COVID-19 efforts

The poor countries of the world can’t afford COVID-19 vaccine , so the World Health Organization and other groups have banded together to collect funds from rich countries to support vaccine efforts in those countries. On Friday (Feb. 19), the effort, called COVAX, vaccine announced a combined pledge of $4.3 billion from G7 (U.S., Germany, the European Commission, Japan and Canada).

COVAX is the vaccine-focused part of a larger organization called the Access to COVID-19 Tools (ACT), which also takes in treatment and diagnostics. ACT says it needs $38.1 billion in in 2020-21 and has pledges of $10.3 billion so far.

Don’t be picky about which vaccine you get, says Brown public health dean Jha

The FDA’s Vaccines and Related Biological Products Advisory Committee (VRBPAC) is scheduled to meet on Friday (Feb. 26) to discuss the EUA for Johnson & Johnson’s one-dose COVID-19 vaccine. If things go as expected the FDA will approve the vaccine soon afterwards, so there will be three vaccines available in the U.S. come mid-March.

But study results show that the J&J vaccine is 66% effective at preventing moderate to severe COVID-19. The Pfizer-BioNTech and Moderna vaccines that already have EUAs are 95% effective. There’s a good chance the J&J vaccine will be deemed inferior, at least in the court of public opinion. Americans might very well hold out for getting the “superior” Pfizer-BioNTech and Moderna vaccine.

In an opinion piece published by the Washington Post on Tuesday (Feb. 16) Ashish Jha, the dean of Brown University’s new School of Public Health, tried to damp down such thinking.

“The vaccines in front of us exceed everyone’s expectations for safety and preventing hospitalizations and deaths,” wrote Jha, who has a big Twitter following (for a public health official). “Any vaccine that turns COVID-19 from a deadly pandemic that has killed nearly half a million Americans into a mild disease that allows us to get our lives back is a vaccine worth taking.

Jha wrote that the most important finding from the main clinical trial for the J&J vaccine is that the vaccine was 100% effective at preventing hospitalizations and deaths from COVID-19.