How single dose Johnson & Johnson vaccine could affect public health strategy

Pending Johnson & Johnson single dose vaccine would help with hard-to-reach populations

Laura Vanier with the Nashville Health Department shows the socially distanced area where patients line up to receive the COVID-19 vaccine. / Photo by John Partipilo

A wave of new COVID-19 vaccines appears to be on the horizon, bringing with them the expanded possibilities of reaching people outside traditional health care settings and with only one dose.

Two vaccines, from Pfizer/BioNTech and Moderna, have been granted emergency approval by the Federal Drug Administration. Those are the vaccines Tennesseans have been receiving so far.

A new vaccine developed by Johnson & Johnson, which has applied for FDA approval, could receive approval by the end of this month. And promising clinical trial data for vaccines developed by Oxford University/Astrazeneca and Novavax seemingly puts those candidates on track for FDA approval as well.

The vaccines are not the same. They were developed with different technologies, are stored at different temperatures and, most importantly, require a different number of shots.

But experts and public health officials say the vaccine options have one critical thing in common: they are immensely effective at preventing hospitalizations and severe bouts of COVID-19.

"It's incredible," said Dr. Buddy Creech, director of the Vanderbilt University Vaccine Research Program. "With the two vaccines we have under emergency use now, and with Johnson & Johnson, we now have three really good tools to curb the pandemic.

"What I think is important to say is we have nearly 100 percent efficacy in clinical trials at preventing COVID-19-related hospitalization and death. And that is what will turn the tide."

Creech touted the efficacy of all three vaccines in response to a question about the most recent data from Johnson & Johnson, which showed 72 percent efficacy in preventing participants in the clinical trial from getting moderate to severe cases of the virus. The vaccine proved effective 28 days after being administered at preventing serious cases of COVID-19.

Although the Pfizer and Moderna vaccines, which use cutting-edge messenger RNA technology, are more effective at preventing moderate cases, health experts said individuals shouldn't worry about shopping around for different vaccines.

The Johnson & Johnson vaccine also appeals to public health officials because it is administered in a single dose, unlike the current vaccines that need two. The Johnson & Johnson vaccine is also simpler for the state and local health departments to administer because it can be stored in refrigerators.

"We anxiously await the Johnson & Johnson vaccine because it is a single dose, refrigerated vaccine," Dr. Michelle Fiscus, FAAP, medical director of the TDH Vaccine-Preventable Diseases and Immunization Program, said in written comments sent through a spokeswoman. "A single dose vaccine is attractive because we currently spend so much effort providing second vaccine doses when we could be vaccinating more people. Vaccinating everyone once is much easier than vaccinating everyone twice."

Dr. Alex Jahangir, who co-chairs Metro Nashville's coronavirus task force, pointed out that when the pandemic first took hold, experts across the nation were hoping for vaccines that were even 50 percent effective at preventing severe illnesses. In less than a year, as many as five options have been developed.

"It really is amazing and it shows what can be accomplished when researchers, and governments and stakeholders at the various levels work together in a global way toward a common goal," Jahangir said.

The game changer, in terms of public health strategy in disseminating the vaccine, could be the fact Johnson & Johnson's vaccine doesn't need to be stored or transported at sub-zero temperatures.

Fiscus said the state will follow the Advisory Committee on Immunization Practices for guidance on whether to target specific demographics with different vaccines. Demographics that are difficult to reach, and to schedule for two doses, could be targeted with the single-dose option.

Fiscus acknowledged that the Johnson & Johnson vaccine offers advantages because it is easier to store.

"Vaccines that only require refrigeration are definitely preferred over those that require frozen storage, as they're easier to handle and less vulnerable to temperature excursions that might make them unusable," she said.

Jahangir said the refrigeration storage could offer possibilities for the Metro health department. Already, Metro has utilized a mobile immunization strategy, bringing the vaccine directly to residents at the Metro Center teachers apartments and a dialysis center. Jahangir speculated that new vaccines could bring advantages in partnering with churches and other community groups, since the only infrastructure needed to store the vaccine is a refrigerator.

The pending Johnson & Johnson vaccine comes with two advantages: it can be administered in a single dose, instead of two doses, and requires simple refrigeration rather than sub-zero temperatures.

"It allows us to distribute it even more broadly," Jahangir said. "If we have even more availability of getting vaccines that don't need the storage, we can do more church events. Or let's say there's a fair of some sort that brings people together, you can vaccinate people much more easily."

The good news on the vaccines comes with a caveat. The discovery of new strains of the COVID-19 virus in the United Kingdom and South Africa has led to the question of how effective the vaccines will be against them. Jahangir said officials will monitor effectiveness against those strains and whether the vaccines already on the market can be tinkered with in the same way flu vaccines are altered.

"There's a lot of worry about the South African version and the efficacy of any vaccines we have on the market against that," Jahangir said, pointing out that initial data shows the vaccines are still very effective against the U.K. variant.

Jahangir said the rise of the variants is why people should remain vigilant, wear masks, social distance when possible and follow the other protocols that have become entrenched in society in the last year.

Creech, the head of Vanderbilt's research program, said that while the data on overall effectiveness may vary from vaccine to vaccine, the bottom line is each candidate is showing the ability to save people from having to go to the hospital.

"We've got to realize that our goal in this pandemic is to stop people from having severe disease, hospitalizations and death," Creech said. "If we can do that, if COVID-19 becomes nothing more than a cold that lasts a couple of days and you don't even have a fever with it, everybody's happy."

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