Brief Notes on Covid-19 Vaccines as compiled by GCEM Hospital for public use:
1 There are about three verifiable vaccines in circulation namely
(a)Pfizer / BioNTech ( BNT162b2) ( b) Morderna ( mRNA-1273) (c)Astra zeneca( (Oxford vaccines.)
2 our focus will be on Pfizer/ BioNTech and Moderna vaccine that has gotten emergency authorization in USA and Europe.
Similiariities of the two vaccines.
a)Both vaccine are formulated to work based on novel messengerRNA (mRNA) mechanism.
b) In both vaccine ,no LIVE Virus is involved and no Genetic material enters the Nucleus of the cells. No chips in inserted in the body.
C) Both requires cold storage temperatures. For Pfizer/BioNTech. Temp of-70 degree centigrade(ultra cold freezers )while that of Moderna is about -20 degrees centigrade.
d) Both vaccine have to be given by intramuscular route ( deltoid muscle/ upper arm)
e) Both vaccine requires that two full doses be taken for effective protection because 95 % vaccine efficacy result comes after the second dose which boost the immune response and makes it more durable.
f) Both vaccine have a grace period of 4 days ( considered as valid) around the 21 or 28 day interval for the administration of second dose .
f) No information on durability of protection for both vaccine but for Moderna vaccines , antibodies persisted for about 4 months with a decline over time.
g) Both vaccines prevented severe covid-19 diseases in individual and seems to prevent asymptomatic transmission as well.
h) Even after vaccination, individual will still ensure hand washing, social distancing, wearing of face mask, and avoidance of crowded indoor settings.
Differences in the two vaccines include:
a) For Pfizer/BioNTech. Temp of -70 degree centigrade(ultra cold freezers )is needed and after thawing ,must be used within 5 days While that of Moderna is about -20 degrees centigrade and is stable at refrigerator temperature for 30 days.
b) Minimum shipment size for Pfizer/ BioNTech is about 975 doses while that of Moderna vaccine is 100- doses batches
c) For Pfizer/ BioNTech vaccine , second dose is received 21 days after( day22) while second dose of Moderna vaccine should be give 28 days after. A 4 day grace period around these days of the second dose is acceptable as valid.
d) Pfizer/ BioNTech vaccine is approved for ages >16yrs while Moderna is approved for ages >18yrs.
Basic information on how the Vaccines works in your Body
Once the vaccine is injected in the upper arm,the mRNA in the vaccine is taken up by macrophages ( a component of immune system that surrounds and kills micro organisms, removes dead cells and stimulate other immune system cells) near the injection site and now instruct this macrophages to make SARS-coV-2 “spike proteins” prickly projections on the surface of corona virus. After making the spike proteins, they are directed to appear on the surfaces of these macrophages, inducing immune response that follows the pattern of the way we fight off infections , thereby offering protecting from the natural infection with SARS -coV-2(covid-19). Thereafter, enzymes in the body now degrade and dispose the mRNA.hence no live virus and no genetic material is inserted into the nucleus of the cells.
General information that may be of interest to you include the following :
1) There will be pain on injection site especially 12 to 24 hours after administration. Only in 1% people are the pain so severe.Fatigue and headache are relatively common side effects also but high fevers are not common. These have been attributed to the two vaccines being “reactogenic”- meaning a reflection of the brisk immune response they generate. Paracetamol and / or ibuprofen usually resolves this. However, it is advisable you do not take this medication ahead of receiving the vaccine just because you want to avoid experiencing the side effect. This is to avoid blunting your immune response when given the vaccine.
2) If you had covid-19 and were treated with monoclonal antibodies or convalescent plasma.it is advisable you wait for about 90 days before receiving the vaccine. These form of treatment theoretically appears to reduce the efficacy of the vaccine but protects you during this time period. When 90 days elapse, you need to get vaccinated.
3)!If one gets the first dose and test positive, it’s is advisable one recovers from acute illness before taking the second dose. The 21 or 28 days interval may not rigidly apply any longer.
4) An observation for 15 minutes is requires after receiving the vaccine so as to watch out for any immediate allergic reaction .For those with history of allergic reaction, the time to wait for observation is 30 minutes. But where there is history of severe allergic reaction especially in the first dose, second dose should not be taken.
5) People with following condition…cancers, solid – organ transplant, bone marrow transplant, stem cell for cancer treatment, HIV, intravenous steroids user and patient on immunosuppressant drugs are at increased risk for severe covid-19 .So they need to be prioritized to receive vaccines early while still emphasizing non pharmacological measures of prevention in these vulnerable groups.
6) For now, children younger than 16 year , pregnant women and breast feeding mother have not been authorized to receive the vaccine. It’s not that the vaccine may not be safe for these group but studies done using these vaccines did not include such category of participants.
7) Ensure that your second dose is of the same brand of vaccine as the first dose. No studies has been conducted to certify safety of receiving two different brands of the vaccine. So start with a brand and complete the second dose with same brand within the interval period for each.
8) Currently, no test is recommended to determine post immunization protection. However,it is estimated that immunity is established 10-14 days after second dose. This may change in the future and may bring up the concept of booster doses.
9) These vaccines will not influence the result of PCR or antigen testing for covid-19 disease. Where one is already positive for disease, it’s is advisable the disease be treated and negative test obtained before you receive vaccination.
My take/ conclusion :African Nations especially Nigeria should look towards Moderna vaccine procurement because of storage, transportation ,distribution and logistic problem than vaccine that require ultra cold storage facilities .Negotiating for possible Patency right from the vaccine manufacturers will reduce cost and make the vaccine more available, accessible, and affordable.
GCEM hospital provided this information to enable you make informed decision regarding your health and life as the pandemic rages
For your questions/ inquiry or other medical resources, you can visit www.gcemhospital.com or Facebook page: GCEM Hospital or Twitter account @drOkangbaBC.
Dr Okangba B.C
A Fellow of West African college of surgeon, A Medical Consultant and Public health Advocate.
Currently, he is the Medical Director of GCEM Hospital(www.gcemhospital.com)
Many thanks to Prof Sax MD, a professor of medicine at Harvard Medical school for material used.