CMAAO Coronavirus Facts and Myth Buster: COVID Update
With input from Dr Monica Vasudev
1283: Indonesia’s Muslims ask Is the vaccine halal?: After waiting months to receive an answer from Sinovac, the Chinese manufacturer, a one-sentence response was received by the clerics: The vaccine was “manufactured free of porcine materials.” Religious leaders are asking for more details, as even the smallest amount of pork DNA could deter some devout Muslims from taking it. President Joko Widodo dismissed the concerns and stated that the emergency virus situation was the greater priority. It’s possible that a fatwa may be issued. Islamic authorities in other countries with large Muslim populations, such as Malaysia and the U.A.E., have already permitted the vaccine. (NY Times)
1284: Late and flawed guidance from the CDC Advisory Committee on Immunization Practices (ACIP) did not differentiate frontline COVID-19 workers from all healthcare workers. Among healthcare professionals, a 61-year-old ICU nurse should receive the vaccine right now, while a young healthy clinician who injects Botox for a living and contracted the infection in the past should step aside. The guidance also did not deprioritize those who already had the infection unless they had it in the last 90 days. ‘Natural immunity may last as long or nearly as long as vaccinated immunity’ is a question that will be answered over time. After one year, re-infections appear to be rare and when they do occur, they are mild.
COVID-19 infection occurs in nearly 5% of vaccinated individuals.
Around 10% of the U.S. nursing home population has been lost from COVID-19 and 80% of all deaths have been in people above 65 years of age. An additional 15% of the deaths are among those with known co-morbidity. Let’s vaccinate these vulnerable Americans before the young and healthy who are not on the frontlines of COVID-19.
Europe is using age and risk of mortality as the major criteria in their vaccine allocation. Prioritizing by risk of mortality maximizes the number of lives saved and reduces the influx of infected COVID-19 patients presenting to a hospital. (Medpage Today)
1285: Switching and Spacing Vaccine Doses: Countries are looking at ways to stretch the limited supplies of COVID-19 vaccines, including by delaying second doses, reducing dose sizes and switching vaccine types between the first and second shots.
All COVID-19 vaccines approved thus far are designed to teach the immune system to recognize and defend against the virus with a first dose, followed by providing a second booster dose to reinforce the teaching. Amid fast-spreading pandemic and new, more transmissible variants, some countries are hoping to widen immunization by extending some amount of protection to as many people as possible with a first dose, and delaying second doses. Maximizing the number of people who have partial immunity should be able to reduce the number of severe COVID-19 cases and relieve the burden on hospitals, stated Michael Head, a global health expert at Britains University of Southampton.
The same goal drives the idea of mixing or switching between COVID-19 vaccines – vaccinating as many people as possible. Giving a priming dose of one vaccine and a booster dose of the other one provides the flexibility to offer whichever shots are available, rather than holding shots back.
Officials cite limited evidence from trials that the Pfizer/BioNTech, the Oxford University/AstraZeneca and the Moderna vaccines all confer some protection against COVID-19 after the first dose.
Pfizer/BioNTech vaccine conferred 89% protection from two weeks after the first dose, while evidence for the Oxford/AstraZeneca vaccine shows that the initial dose offers as much as 70% protection against the effects of the virus.
Moderna’s vaccine was reportedly 80% protective after one dose, with efficacy peaking two weeks after the first shot.
BioNTech and Pfizer have cautioned that they had no evidence that their vaccine would continue to be protective if the second dose was given more than 21 days after the first.
In the United States, some health officials are even considering giving half doses of Modernas vaccine to individuals aged 18 to 55. There is some clinical trial data to support this strategy.
Moncef Slaoui, chief adviser to the U.S. Operation Warp Speed vaccine programme Operation Warp Speed, told CBS that evidence from a Moderna trial demonstrated that the half dose induced an identical immune response to the higher 100 microgram dose in adults aged 55 and below. He said that the U.S. government was in talks with Moderna and regulators.
- While there was no evidence to support the strategy of mixing vaccine doses from different manufacturers – a method called heterologous prime-boost – evidence from other vaccines provided some reassurance.
- Based on previous studies combining different vaccine types, a combination of the AstraZeneca and Pfizer vaccines is likely to be safe.
- There is potential for adverse reactions or a significant drop-off in efficacy.
- Safety issues, especially with delaying the second dose for several weeks are also there. The gap could enable the virus to evolve and develop resistance to the vaccine.
- Weak antibody protection could also heighten the risk of having an abnormal immune response – such as antibody-dependent enhancement – when people are exposed to the real virus.
- Extending the interval is associated with adherence risks, increasing the odds that people may forget or fail to return for a second dose.
- It also increases the length of time during which they are less than optimally protected.
- It could make it harder for health authorities to track who has had which vaccine, when, and how often.
1286: Infectious Diseases Society of America (IDSA) Panel Updates Guidelines on COVID Molecular Diagnostic Tests
- The panel noted that saliva tests were particularly effective if the test included instructions to cough or clear the throat prior to spitting into the tube.
- Using a throat swab alone was less effective and missed more cases compared to other methods.
- Recommendation: A saliva test or swabs from either the middle or front of the nose front are preferable over a throat swab alone.
- A combination of saliva and swabs from the front and middle of the nose and throat together appeared equivalent to the gold-standard deep swab.
- Saliva samples do have challenges. A laboratory must validate that its systems are able to handle the stickier material. Additionally, asking a patient to cough necessitates more personal protective equipment (PPE) for the healthcare professional.
- The only rapid isothermal test that had enough data on which to issue a recommendation was the ID NOW test (Abbott Labs). (Medscape)
1287: Anaphylaxis cases after COVID vaccines rising, but still rare: CDC
There have been 29 reports of anaphylaxis till today following administration of a COVID-19 vaccine. The severe allergic reaction appears to be rare, and can occur with either the Pfizer-BioNTech vaccine or the Moderna vaccine.
There have been nearly 11.1 cases of anaphylaxis per million doses with the Pfizer-BioNTech COVID-19 vaccine, which is higher than the estimated 1.3 cases per million doses with influenza vaccines.
The low risk of anaphylaxis has to be balanced against the threat of COVID-19, which is claiming about 2000 lives a day in the United States. Furthermore, several people are reporting long-term complications with COVID-19 even if they recover.
The CDC has also provided an update on anaphylaxis in Morbidity and Mortality Weekly Report (MMWR).
The information was based on cases reported with the Pfizer-BioNTech vaccine. From December 14 to 23, monitoring by the Vaccine Adverse Event Reporting System identified 21 cases of anaphylaxis after administration of some 1,893,360 first doses of the Pfizer-BioNTech COVID-19 vaccine. Most reactions (71%) occurred within 15 minutes of vaccination. (Medscape)
1288: Early Use of High-Titer Plasma: Administering convalescent plasma with high levels of antibodies against SARS-CoV-2 within the first 3 days of symptoms was tied to significantly lower odds of progression to severe COVID-19. A trial of 160 older adults with COVID-19 randomized half to receive plasma and half to receive placebo infusion. Treatment with high-titer plasma decreased the relative risk for severe disease by 48% in an intent-to-treat analysis.
“Not any plasma, not any time,” stated senior author Fernando Polack. The key is to select plasma in the upper 28th percentile of IgG antibody concentrations and to administer therapy before disease progression. The study was published online in The New England Journal of Medicine. (Medscape)
Dr KK Aggarwal
President CMAAO, HCFI and Past National President IMA