July 01, 2020, 03:00 pm Michael Devitt – Not surprisingly, COVID-19 was a hot topic during the CDC's Advisory Committee on Immunization Practices' first-ever virtual meeting last week. ACIP members received updates on various aspects of the pandemic and also discussed issues related to vaccines for influenza and meningococcal disease.
The ACIP spent much of the June 24 meeting -- one of three it convenes each year -- discussing the COVID-19 pandemic and its effects on the U.S. health system. Topics included SARS-CoV-2 immunology, disease epidemiology, routine vaccination procedures during the pandemic and issues associated with potential COVID-19 vaccines being developed.
Notably, of the roughly 2.3 million cases of COVID-19 diagnosed in the United States as of June 23, committee members learned that 83,673 cases had occurred among health care personnel, with 464 deaths.
AAFP liaison to the ACIP Pamela Rockwell, D.O., of Ann Arbor, Mich., told AAFP News that according to materials presented during the meeting, the five most common symptoms of COVID-19 were, in descending order of frequency, fever, cough, myalgia, headache and diarrhea. No particular set of signs or symptoms has been shown to reliably distinguish COVID-19 from other respiratory viral illnesses, although a recent literature review indicates that anosmia and/or dysgeusia may be strongly correlated with SARS-CoV-2 infection.
Rockwell did note that COVID-19 can produce some unique complications, including diffuse endotheliitis, local and embolic hypercoagulability, and pre- and postinfectious hyperimmune reactions such as myocarditis and multiorgan inflammatory syndrome in children.
One particularly notable development announced during the meeting was the creation of a COVID-19 ACIP Work Group, which formed in April and will be chaired by Beth Bell, M.D., M.P.H., a clinical professor in the Department of Global Health at the University of Washington in Seattle.
"The work group comprises 41 members from a wide array of medical backgrounds and expertise, including ACIP voting members, liaisons (including AAFP liaison Jonathan Temte, M.D., Ph.D., M.S.) ex-officios and expert consultants who stand for the principles of evidence-based decision-making, equity and transparency," Rockwell explained. Temte, who served as a longtime ACIP member and was the first FP to chair the committee, is a professor in the Department of Family Medicine and Community Health and associate dean for public health and community engagement at the University of Wisconsin School of Medicine and Public Health in Madison.
According to Rockwell, the work group's goals include preparing for the introduction of safe and effective COVID-19 vaccines, reducing disease transmission and associated morbidity and mortality, helping to minimize disruptions to society and the economy (including health care capacity), and ensuring equity in vaccine allocation and distribution.
Multiple platforms will be utilized to increase the chances of developing safe and effective vaccines that can meet national and global demand, Rockwell explained, with clinical vaccine trials following stringent safety standards. At present, vaccine characteristics such as recommended number of doses, route of administration and proper storage details remain unknown.
The work group's next steps will be to define the benefits and risks of the evidence-to-recommendations framework that will be used to assess the vaccine program and help groups move from evidence to ACIP recommendations, review clinical trial data for candidate vaccines, advance understanding of safety issues, further refine tier groups for allocation of early vaccines, and review proposed implementation strategies.
Robert Atmar, M.D., chair of the Influenza Vaccines Work Group, provided preliminary disease burden estimates from the 2019-2020 influenza season. According to his report, between Oct. 1, 2019, and April 4, 2020, there were an estimated 39 million to 56 million instances of influenza in the United States, resulting in as many as 740,000 hospitalizations -- a rate higher than that seen in four of the five previous flu seasons.
Surveillance date gathered during the season showed that influenza B/Victoria virus was the predominant strain circulating early in the season, with the influenza A(H1N1)pdm09 virus strain predominantly circulating later in the season.
Overall, the influenza vaccine for the 2019-2020 season was found to have a 39% effectiveness rate for all age groups and virus types -- 10% higher than that for the previous season and roughly the same as rates seen during the 2016-2017 and 2017-2018 seasons.
Regarding the work group's proposed 2020-2021 ACIP Influenza Vaccine Statement, committee members voted unanimously to accept the recommendation that annual influenza vaccine be administered to all people 6 months and older who do not have contraindications -- a recommendation identical to that contained in the 2019-2020 statement.
Other 2020-2021 vaccine statement recommendations included
Rockwell also told AAFP News that the composition of the 2020-2021 influenza vaccine will include updated influenza A(H1N1) and A(H3N2) strains, as well as an updated B/Victoria strain. (Those changes reflect virus strains selected for inclusion in the 2020-2021 vaccine by the FDA's Vaccines and Related Biological Products Advisory Committee during its March 4 meeting.)
Given the likelihood that COVID-19 will still be circulating in the United States when flu season arrives, Rockwell said that vaccine manufacturers have pledged to make a concerted effort to ensure adequate and increased supplies of influenza vaccine this year.
"Most scientists predict a devastating influenza season if people are not vaccinated against influenza, especially those in high-risk groups, as coinfection with COVID-19 will worsen outcomes and confer severe morbidity and mortality," Rockwell said, adding a warning for those hesitant to be immunized against influenza.
"If you were ambivalent or on the fence about the influenza vaccine in past years and wondered about the benefit of vaccination, this year, with the ongoing COVID-19 pandemic, is the year to rethink your ambivalence and make sure you get vaccinated! Not only is the influenza vaccine proven to reduce the incidence of influenza, it also reduces overall hospitalizations, ICU admissions, and death even if one contracts the flu," she stressed.
Veronica McNally, J.D., chair of the ACIP's Meningococcal Vaccines Work Group, reported that the FDA in April approved MenQuadfi (MenACWY-TT), the first quadrivalent meningococcal conjugate vaccine to use tetanus toxoid as a protein carrier.
"Conjugate vaccines, unlike polysaccharide vaccines, produce T-cell long-term immunological memory," Rockwell explained. "The use of tetanus toxoid as a protein conjugate enhances vaccine immunogenicity and is of comparable efficacy to other MenACWY meningococcal conjugate vaccines like Menactra and Menveo that are conjugated with a diphtheria toxoid protein carrier. MenQuadfi offers another vaccine in this category."
MenQuadfi has been licensed for use in patients ages 2 years and older, whereas neither Menactra nor Menveo is approved for use in people older than 55. During the meeting, the 14 ACIP voting members in attendance voted unanimously to recommend it as an option in the Vaccines for Children program.
The ACIP's next meeting is scheduled currently for Oct. 28-29. Typically, meetings are held at CDC headquarters in Atlanta, and all ACIP meetings are open to the public and available online via webcast.