> Highest (Real-world use, Effectiveness data & Publication of Efficacy trial):
Pfizer
AstraZeneca
Moderna
> Moderate (Real-world use, Publication of efficacy trial):
JNJ
Sputnik-V
Sinopharm
Novavax
(contd)
4/n
>Low-moderate (Real world data, no publication of efficacy trial):
CanSino
Sinovac
Covaxin
5/n
➡️Israel, Chile, Bahrain, US & UK are the 5 leading countries as far as the highest share of the fully vaccinated population is concerned.
➡️Sinovac’s CoronaVac vaccine fared poorly in Seychelles & Chile.
6/n
➡️Pfizer & AZ vaccines have shown real-world effectiveness & population level impact. Though some level of confounding effects of non-pharmaceutical interventions was also present.
➡️Most vaccines have the highest efficacy against severe disease & deaths.
7/n
➡️No vaccine is 100% efficacious against SARS-CoV-2 SARS-COV-2 transmission infection (NO STERILIZING IMMUNITY).
Except for Pfizer/Moderna vaccines, most vaccines have only modest efficacy against transmission.
8/n
➡️Breakthrough infections observed with almost all vaccines. Most mild & moderate, deaths are also seen in fully vaccinated (out of 5800 breakthrough cases with mRNA vaccines in the US, 7% hospitalized & 74 died)
9/n
➡️Most vaccines have comparatively lower efficacy in the elderly & comorbidities than in younger and healthy people.
➡️Most gene-based vaccines (mRNA & Viral vector) have high reactogenicity profile.
10/n
➡️Adenovirus vector-based vaccines (AZ & JNJ) have rare, serious adverse events called VITT (vaccine-induced immune thrombotic thrombocytopenia).
Incidence varies from 1 case in 40 000 to 1 in 100 000, but the BENEFITS FAR OUTWEIGH THE RISKS.
>Most vaccines have only very modest reductions in efficacy against UK’s B117 & Brazil’s P1 variants.
>Most vaccines have lower efficacy against South Africa’s B1351 variant (containing E484K mutation).
12/n
> AZ vaccine has got only 10% efficacy against B 1.351.
>JNJ (57%) & Novavax (49%) had major reductions in efficacy trials.
>Sputnik-V, Pfizer & Moderna vaccines have reduced neutralization against B1.351.
13/n
> Pfizer vaccine has shown intact efficacy against B1.351 in Qatar in real-world evidence after 2 doses.
>Nevertheless, most leading vaccines are developing boosters with revised formulation to tackle the B1.351 variant.
14/n
➡️So far, natural infection-induced protection seems to be more lasting than vaccine-induced, particularly in the context of non-mRNA vaccines.
>Things are still evolving. This is an observation based on 6-7 months post the trial reports. Too early to conclude anything.
15/n
> Also, the response of the human immune system to the invading virus is not uniform. Many patients with a severe infection also fail to have a good amount of Memory B cells.
>Whereas, with vaccines - such uncertainty can be avoided.
16/n
➡️Only 4 vaccine candidates elicited several folds higher titers of neutralizing antibodies (NAbs) than natural infection (NAbs titers measured in human convalescent serum):
Pfizer
Moderna
Novavax
Sputnik-V.
However, natural immunity is much broader.
17/n
➡️We know that natural infection provides at least 8 months of protection.
>mRNA vaccines are found to provide protection at least for 6 months without any appreciable loss of efficacy.
>Vaccines like inactivated & AZ vaccine may provide a lesser duration of protection.
18/n
➡️Natural infection may provide resistance against immune evader variants also since there are immune responses against not only against S protein but against other antigens of the virus.
Further, the variants do not have changes in T-cell epitopes.
19/n
➡️Most vaccines elicit both humoral and T cell immunity.
> However, viral vector vaccine, particularly the AZ vaccine has got particularly good CD8 cell response which kills the virus-infected cell and ameliorates the severity of the disease.
20/n
➡️Those had natural infection can ideally wait for THREE MONTHS for their Covid vaccine shot. (minimum time to wait is at least 4-6 weeks)
➡️In previously infected individuals with anti-spike IgG positive individuals, only ONE DOSE of mRNA vaccine is sufficient.
21/n
➡️Though no official recommendation from the WHO, still pregnant women can have the vaccine at any stage of pregnancy. Strong data for 3rd trimester with mRNA vaccines.
> FIGO and FOGSI have recommended vaccination of Pregnant women (2nd, 3rd trimester).
22/n
> No known risk in giving COVID-19 vaccines to women who are breastfeeding.
>Women who are breastfeeding should be encouraged to continue breastfeeding after being vaccinated.
23/n
➡️No need to avoid becoming pregnant after having the vaccine.
➡️There is no evidence to suggest that COVID-19 vaccines will affect fertility.
24/n
➡️Several vaccines are now conducting trials in the Pediatric population.
Pfizer - 100% efficacy in 12-15 yrs old.
Moderna - Trials in 6mo to 12 yrs (inUS) & 5-11 yrs (in Canada).
JNJ 12-17 yrs.
Sinovac 3-11 yrs.
Novavax 12-17 yrs.
AZ has paused their trial in 6-17 yrs.
25/n
MYTH: #Lemon juice through the nose will kill the virus.
FACT:
Lemon juice is acidic. Taking undiluted lemon juice through the nose will damage the inner lining, cause irritation, and may cause bleeding as well. It will not kill the virus either. DON'T SNORT LEMON JUICE.
Psychology says humour is one of the most mature defence mechanisms. If you enjoy this humourous video depicting the state of affairs in our country right now, share this and let us know.
Wear masks, Practice Distancing.
- Dr. Devashish Palkar (@DevPalkar)
Dr. Haryax Pathak
P.S. Yeh mat bolna Yeh video Anti-MODI hai. It features RaGa and Didi too.
Basically it's anti-stupidity. 😁🙏