Since pharmaceutical companies Pfizer and Moderna announced that their vaccines for COVID-19 had achieved around 95 percent effectiveness, University researchers have formed insights about their potential impacts.
With the prospect of immunity to COVID-19 closer than ever, researchers from the School of Public Health spoke with The Herald about Pfizer’s trial methods, distribution in Rhode Island, the holiday season and other elements that may hinder or aid the vaccine’s success.
The phase three trial of Pfizer’s vaccine studied the infection rates in a group of around 43,000 participants, with 162 out of the 170 confirmed COVID-19 cases in this cohort coming from those who were given placebos — inactive substitutes offering no immune protection — rather than the vaccine, according to a press release from Pfizer released Nov. 20.
Since the vaccine requires two shots for a person to gain full immunity to the virus, Pfizer observed trial participants two weeks following a second dose, John Fulton, clinical professor of behavioral and social sciences, told The Herald. Fulton is a member of the Rhode Island Department of Health’s COVID-19 Vaccine Subcommittee, which is composed of epidemiologists, medical professionals and other community leaders.
The diversity and representativeness of the sample is important, he said. Unlike a controlled laboratory setting where all case and control group animal subjects may be deliberately infected with the virus, Pfizer has to make the assumption “that they have enough people of diverse backgrounds, personalities, interests, anxieties … that more or less both groups are going to act the same way in the world,” Fulton said. In the study, about “30 percent of U.S. participants have racially and ethnically diverse backgrounds,” according to the press release.
Additionally, the proportion of participants who practice social-distancing and mask-wearing and the proportion who do not should be roughly the same in the groups taking a placebo and receiving the vaccine, Fulton said.
The vaccine has also shown more promise than originally expected among some in the research community. “We feel good about that because we were hoping for at least 50 percent effectiveness,” Fulton said.
Assuming Pfizer’s vaccine is as effective as this recent data suggests, its success will be determined by whether herd immunity — the situation in which a sufficient portion of the population is immune and therefore cannot infect the remainder — is achieved, he said. Herd immunity requires a viral reproduction number of one or less, meaning that an infected person will spread the disease to at most one new person, overall decreasing or eventually eliminating the virus. Rhode Island’s current COVID-19 reproduction rate oscillates between 1.24 and 1.25, so the virus is continuing to infect an increasing portion of the population, according to Fulton.
Rhode Island was chosen by Pfizer as one of its four distribution states, The Herald previously reported. As a distribution state, Rhode Island will work with the pharmaceutical company to help plan effective handling and administration of the vaccine before the vaccine becomes available to the community across the country, according to The Providence Journal.
Assuming general distribution of the vaccine will be proportionate to population size, Rhode Island will receive “0.3 percent of the supply of each vaccine designated for distribution to states in the U.S.,” which could include the vaccines produced by Pfizer and Moderna, according to Fulton. He estimates that the Ocean State will receive between 10,000 and 20,000 doses per week, an amount which will need to cover both shots of the vaccine for each recipient. Previously infected people will also have to be vaccinated given that the disease does not confer lasting immunity, he said. The quantity of shipped vaccines may increase over time if promising vaccines from other companies, such as AstraZeneca, become authorized and available, Fulton added.
Decisions to be made regarding vaccine distribution include who should first receive the vaccines and where they should be offered so that the vaccines can be stored under the proper conditions, Fulton said.
The University is working closely with RIDOH on the vaccine distribution plan and the resources it can provide to support this process, said Russell Carey ’91, executive vice president of planning and policy. For instance, the Pfizer vaccine requires ultra-cold temperatures to store. “We have facilities that are able to support that and (have) communicated that to the state,” Carey added.
A confirmed distributor of the vaccine will include CVS Health, which, according to an announcement Nov. 12, will administer COVID-19 vaccinations to the general public at its pharmacy locations.
Once a vaccine is authorized by the Food and Drug Administration and available to the public, it is possible that the University will provide vaccines to its community members, Carey said.
But “it’s too early to say” whether the University’s testing program will change once the vaccine is offered, Carey said. He anticipates that the current testing program will “continue as it is (going) into and most likely throughout the spring term.”
A difficulty in administering the vaccine may result from the need for two doses, which poses a greater logistical challenge than single-dose vaccines, Fulton said. “We don't know how big a timing-window we have for the second dose to work,” he added.
The RI Vaccine Subcommittee is also currently considering how to ensure that vaccine distribution is not only fast and effective in combating COVID-19, but also reduces disparities, Fulton wrote in an email to The Herald.
COVID-19 case statistics have reflected health disparities since the pandemic began. For example, Hispanic and African-American populations within Rhode Island are being disproportionately affected by COVID-19 — a trend seen nationwide, said Professor of Public Health and Biostatistics Joseph Hogan. Hogan and Taylor Fortnam GS analyze trends in case and hospitalization counts and testing rates for different segments in the population for the state of Rhode Island.
The RI Vaccine Subcommittee is “very concerned” about equitably disseminating information on the vaccine among all populations, Fulton said.
The committee also hopes to reach those who may be hesitant to be vaccinated. “We are not just trying to get information out to people; we are trying to convince them to be vaccinated,” he wrote.
Hogan has previously conducted research on the treatment and prevention of HIV/AIDS. “One big similarity between HIV/AIDS and COVID-19 is, to prevent transmission, we have to modify behavior,” Hogan said. While there have been significant efforts over time to help people take steps to reduce the risk of HIV transmission, the U.S. has not focused on or seen much success in changing people’s behaviors, he added.
Though the new developments with Pfizer and other vaccines are appearing at an accelerated pace with promising results, “there is a real fear that we’re letting our guards down,” Hogan said, noting the approaching holiday season. If people decide to attend social gatherings for the holidays, most likely in an indoor space due to the cold weather, it will create the environment with the highest risk for transmitting the virus, he said.
While the highest case rates in Rhode Island have been recorded in crowded, urban areas, infections and the necessity for preventative measures are not limited to those places. “There's really a very high trajectory increase in (rural) areas like Coventry and Gloucester,” Hogan added.
The vaccine “will take some time to roll out, and we just have to be vigilant until we have widespread vaccination,” he said.
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