US Pharm. 2021;46(4):36-39.

 

Adult Vaccination Recommendations Updated by Public Health Officials

The CDC recently announced changes to the 2021 immunization schedules for adults aged 19 years and older. The updates affect recommendations for vaccines to prevent influenza, hepatitis A (HepA), hepatitis B (HepB), human papillomavirus (HPV), pneumococcal infections, meningococcal serogroups A, C, W, and Y (MenACWY) infections, meningococcal B (MenB) infections, and herpes zoster.

The CDC’s Advisory Committee on Immunization Practices (ACIP) also recommends the use of COVID-19 vaccines within the scope of the Emergency Use Authorization or Biologics License Application for the particular vaccine.

Here are some of the key changes:

• HepA—Text has been added for the accelerated Twinrix schedule: “HepA-HepB combination vaccine or Twinrix may be administered on an accelerated schedule of three doses at 0, 7, and 21–30 days, followed by a booster dose at 12 months.”

• HepB —The recommendation has been changed to indicate that HebB vaccination for adults aged 60 years or older with diabetes is recommended, using shared clinical decision-making.

• HPV—The section now states, “HPV vaccination recommended for all persons through age 26 years.” Under routine vaccination, the text was reformatted to match the Child/Adolescent schedule and now reads, “Age 15 years or older at initial vaccination: three-dose series at 0, 1–2 months, 6 months (minimum intervals: dose 1 to dose 2: 4 weeks / dose 2 to dose 3: 12 weeks / dose 1 to dose 3: 5 months; repeat dose if administered too soon).” It adds that no additional doses of HPV are recommended after completing a series at the recommended dosing intervals using any HPV vaccine. Other changes involve shared clinical decision-making.

• Influenza—Guidance was changed on allergy monitoring, i.e., “If using an influenza vaccine other than RIV4 or ccIIV4, administer in medical setting under supervision of health care provider who can recognize and manage severe allergic reactions.” It also clarifies when a severe allergic reaction is a contraindication to future receipt of the vaccine and points out that the specific LAIV4 version should not be used if influenza antiviral medications oseltamivir or zanamivir were received “within the previous 48 hours, peramivir within the previous 5 days, or baloxavir within the previous 17 days.”

• Meningococcal vaccination—MenQuadfi (MenACWY-TT) vaccine was added to all relevant sections because it is now licensed. For both MenA and MenB, text updates recommendations about boosters in special situations and in outbreak setting (e.g., in community or organizational settings and among men who have sex with men). 

• Pneumococcal vaccination—The advice has been updated for routine vaccination in those aged 65 years and older. Under the Shared Clinical Decision-Making section, bullets have been reordered as follows:

–PCV13 and PPSV23 should not be administered during the same visit.

–If both PCV13 and PPSV23 are to be administered, PCV13 should be administered first.

–PCV13 and PPSV23 should be administered at least 1 year apart.

• Tdap—Wound management information has been updated for patients with three or more doses of tetanus-toxoid–containing vaccine, “For clean and minor wounds, administer Tdap or Td if more than 10 years since last dose of tetanus-toxoid–containing vaccine; for all other wounds, administer Tdap or Td if more than 5 years since last dose of tetanus-toxoid–containing vaccine. Tdap is preferred for persons who have not previously received Tdap or whose Tdap history is unknown. If a tetanus-toxoid–containing vaccine is indicated for a pregnant woman, use Tdap.”

• Zoster vaccination—References have been removed to previous receipt of (zoster vaccine live or Zostavax [ZVL]) dose when considering vaccination of persons aged 50 years or older with recombinant zoster vaccines or Shingrix (RZV). In addition, the bullet about ZVL for persons aged 60 years or older was deleted because ZVL is no longer available in the U.S. market.

 

Recombinant Subunit Herpes Zoster Vaccine Safe in Transplant Patients

Although immunization of varicella-zoster virus (VZV)-seronegative solid organ transplant (SOT) patients using the live-attenuated varicella vaccine is generally contraindicated, use of the recombinant subunit herpes zoster vaccine (RZV) appears safe. The report in the journal Transplantation points out that the product is indicated for VZV-seropositive persons to prevent shingles but could potentially also protect VZV-seronegative persons against varicella.

Swiss researchers working with the CDC in Atlanta performed a safety and immunogenicity evaluation of RZV in VZV-seronegative SOT recipients as an option for protection. Included in the study were 23 VZV-seronegative adult SOT patients with no history of varicella/shingles vaccine or disease; participants were given two doses of RZV vaccine 2 to 6 months apart. The median age was 38 years, and the median time since transplant procedure was 3.8 years among the patients, with the most frequent transplant types being liver (35%) and lung (30%). 

Blood draws occurred prevaccination (V1), prior to the second dose (V2), and 4 weeks after the second dose (V3). Researchers evaluated humoral (anti-gE) and cell-mediated immunity, with polyfunctional cells defined as cells producing ≥2 cytokines.

The results indicate that median anti-gE levels significantly increased from V1 to V3 (P = .0001) and V2 to V3 (P <.0001), even though only 55% had a positive seroresponse. The authors point out that median polyfunctional CD4 T-cell counts increased from V1 to V2 (54/10 vs. 104/10 cells; P = .0041) and from V2 to V3 (380/10; P = .0002), with most adverse events mild and no rejection episodes.

“RZV was safe and elicited significant humoral and cellular responses in VZV-seronegative SOT patients and has the potential to be considered as a preventive strategy against primary varicella,” the researchers conclude.

Another study in the American Journal of Transplantation looked specifically at the safety and immunogenicity of RZV in lung-transplant recipients. Canadian researchers and colleagues, including CDC representatives, note that lung-transplant recipients are at high risk for herpes zoster and that preventive measures are a significant unmet need.

The study team investigated the safety and immunogenicity of two doses of a recombinant zoster vaccine (RZV) in lung-transplant recipients aged 50 years and older. Enrolled were 50 patients, 49 of whom received at least one vaccine dose.

These results indicate that antiglycoprotein E (gE) antibody levels in 43 of them increased significantly compared with baseline (median optical density [OD] 1.96, interquartile range [IQR] 1.17-2.89) after the first (median OD 3.41, IQR 2.54-3.81, P <.0001) and second vaccine dose (median OD 3.63, IQR 3.39-3.86, P <.0001). Researchers describe how gE-specific polyfunctional CD4+ T-cell frequencies in 38 participants also increased from baseline (median 85 per 106 CD4+ T-cells; IQR 46-180) to the first (median 128 per 106 CD4+ T-cells; IQR 82-353; P = .023) and after the second dose (median 361 per 106 CD4+ T-cells; IQR 146-848; P <.0001).

In terms of adverse reactions, tenderness (83.0%; 95%CI: 69.2%-92.4%) and redness (31.9%; 95%CI: 19.1%-47.1%) at injection site were common, they write. In addition, the study team observed one rejection episode within 3 weeks of vaccination.

“This is the first study demonstrating that RZV was safe and elicited significant humoral and cell-mediated immunity in lung transplant recipients,” the authors conclude. “RZV is a new option for the prevention of shingles in this population.”

 

Intent to Get COVID-19 Vaccine Increases, Especially Among Older Americans

Overall, U.S. adults’ willingness to be vaccinated against COVID-19 is increasing, especially among older cohorts. The less-positive news is that high percentages of some of the most at-risk groups, including non-Hispanic Black adults, continue to say they have no intention of  being immunized.

Although national polls conducted before vaccine distribution began suggested that many Americans were hesitant to receive COVID-19 vaccination, willingness to be immunized appeared to increase significantly at the end of 2020.

A report in the Morbidity & Mortality Weekly Report notes that from September to December 2020, intent to receive COVID-19 vaccination increased from 39.4% to 49.1% among adults and across all priority groups, while vaccine refusal decreased from 38.1% to 32.1%.

Researchers from the CDC advise, however, that despite decreases in nonintent from September to December, younger adults, women, non-Hispanic Black adults, adults living in nonmetropolitan areas, and adults with less education and income and without health insurance continue to have the highest estimates of hesitancy to receive COVID-19 vaccination.

“Ensuring high and equitable vaccination coverage among all populations, including by addressing reasons for not intending to receive vaccination, is critical to prevent the spread of COVID-19 and bring an end to the pandemic,” the authors write.

As of February 8, 2021, 59.3 million doses of vaccines to prevent COVID-19 had been distributed in the U.S., and 31.6 million persons had received at least one dose of the COVID-19 vaccine, according to the report. 

The article notes that from September to December 2020, vaccination intent increased among all adults by approximately 10 percentage points and across all priority groups, with the largest increase in intent to be vaccinated among adults aged 65 years and older. In fact, nonintent decreased among all adults by 6 percentage points and across most sociodemographic groups.

“However, despite increases in vaccination intent since September, only about half of persons aged 18–64 years surveyed in December reported being very likely to receive COVID-19 vaccination, even among those who were essential workers and persons aged 18–64 years with underlying medical conditions,” the authors explain.

To examine perceptions toward COVID-19 vaccine and intentions to be vaccinated, from September 3 to October 1, 2020, the CDC conducted household panel surveys among a representative sample of about 3,500 U.S. adults. Vaccination intent—defined as being absolutely certain or very likely to be vaccinated—increased overall (from 39.4%-49.1%), with the largest increase occurring among adults aged ≥65 years.

During December 18 to 20, meanwhile, the CDC sponsored questions on two probability-based household panel omnibus surveys—Ipsos KnowledgePanel and NORC AmeriSpeak—administered to 2,033 panelists to reassess COVID-19 vaccination intent and related perceptions.

If defined as being absolutely certain, very likely, or somewhat likely to be vaccinated, vaccination intent increased overall from September (61.9%) to December (68.0%), public health officials state. Vaccination nonintent (defined as not intending to receive a COVID-19 vaccination) decreased among all adults (from 38.1% to 32.1%) and among most sociodemographic groups.

Intent to receive COVID-19 vaccine increased:

• Among adults aged ³65 years by 17.1 percentage points (from 49.1% to 66.2%)

• Among essential workers by 8.8 points (from 37.1% to 45.9%)

• Among adults aged 18 to 64 years with underlying medical conditions by 5.3 points (from 36.5% to 41.8%).

Many of the groups expressing hesitancy have been disproportionately affected by COVID-19, including Black persons and those with lower educational attainment, the article points out, adding, “Because many of these groups are at increased risk for COVID-19–associated morbidity and mortality, COVID-19 vaccination is important for protecting the health of these populations and reducing health inequities.”

The authors recommend continuing to promote vaccine confidence by tailoring information to address concerns of individual persons and communities.

“Health care providers are known to be a trusted source of information about vaccines for many persons and can use CDC-recommended guidance to have effective conversations with patients about the need for vaccination,” they add. “Ensuring high and equitable vaccination coverage in all populations is critical to preventing the spread of COVID-19 and bringing an end to the pandemic.”


Pregnant Women Show Robust Immune Response to COVID-19 Vaccines, Pass Antibodies to Newborns

In the largest study of its kind to date, researchers at Massachusetts General Hospital (MGH), Brigham and Women’s Hospital, and the Ragon Institute of MGH, MIT, and Harvard have found the new mRNA COVID-19 vaccines to be highly effective in producing antibodies against the SARS-CoV-2 virus in pregnant and lactating women. They also demonstrated the vaccines confer protective immunity to newborns through breast milk and the placenta.

The study, published in late March in the American Journal of Obstetrics and Gynecology, studied 131 women of reproductive age (84 pregnant, 31 lactating, and 16 nonpregnant), all of whom received one of the two new mRNA vaccines: Pfizer/BioNTech or Moderna. The vaccine-induced titers—or antibody levels—were equivalent in all three groups. Reassuringly, side effects after vaccination were rare and comparable across the study participants.

“This news of excellent vaccine efficacy is very encouraging for pregnant and breastfeeding women, who were left out of the initial COVID-19 vaccine trials,” said Andrea Edlow, MD, MSc, a maternal-fetal medicine specialist at MGH, director of the Edlow Laboratory in the Vincent Center for Reproductive Biology, and co–senior author of the study. “Filling in the information gaps with real data is key—especially for our pregnant patients who are at greater risk for complications from COVID-19. This study also highlights how eager pregnant and lactating individuals are to participate in research.”

According to the CDC, individuals who are pregnant are more likely to become severely ill with COVID-19 and require hospitalization, intensive care, or ventilation—and may be at increased risk for adverse pregnancy outcomes. The team also compared vaccination-induced antibody levels with those induced by natural infection with COVID-19 in pregnancy and found significantly higher levels of antibodies from vaccination.

Vaccine-generated antibodies were also present in all umbilical cord blood and breastmilk samples taken from the study, showing the transfer of antibodies from mothers to newborns.

“We now have clear evidence the COVID vaccines can induce immunity that will protect infants,” said Galit Alter, PhD, core member of the Ragon Institute and co–senior author of the study. “We hope this study will catalyze vaccine developers to recognize the importance of studying pregnant and lactating individuals and include them in trials. The potential for rational vaccine design to drive improved outcomes for mothers and infants is limitless, but developers must realize that pregnancy is a distinct immunological state, where two lives can be saved simultaneously with a powerful vaccine. We look forward to studying all vaccine platforms in pregnancy as they become available.”

The study also provides insight into potential differences between the immune response elicited by the Pfizer vaccine compared with the Moderna vaccine, finding the levels of mucosal (IgA) antibodies were higher after the second dose of the Moderna vaccine compared with the second Pfizer dose.

“This finding is important for all individuals, since SARS-CoV-2 is acquired through mucosal surfaces like the nose, mouth, and eyes,” said Kathryn Gray, MD, PhD, an obstetrician at Brigham and Women’s Hospital and a first author of the paper. “But it also holds special importance for pregnant and lactating women because IgA is a key antibody present in breast milk.”

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