במשרד הבריאות מעריכים כי החיסון מגן פחות מפני הדבקה בזן האומיקרון

Scientists use whole genome analysis to confirm which variant has caused a Covid infection, but PCR tests can sometimes give an indication. About half of the PCR machines in the UK look for three genes in the virus, but Omicron (and the Alpha variant before it) test positive on only two of them. This is because Omicron, like Alpha, has a genetic change called a deletion in the “S” or spike gene. The glitch means that PCR tests that display so-called “S gene target failure” are highly suggestive of Omicron infections.

We present data on COVID-19 cases, hospitalisations and deaths by vaccination status. These raw data should not be used to estimate vaccine effectiveness as the data does not take into account inherent biases present such as differences in risk, behaviour and testing in the vaccinated and unvaccinated populations. Vaccine effectiveness is measured in other ways as detailed in the ‘Vaccine Effectiveness’ Section.

Vaccine effectiveness is measured in other ways as
detailed in the ‘Vaccine Effectiveness’ Section.

Conclusions
Current evidence suggested that vitamin D deficiency or insufficiency was not significantly linked to susceptibility to COVID-19 infection or its associated death. Vitamin D supplements did not significantly improve clinical outcomes in patients with COVID-19. The overall GRADE evidence quality was low, we suggest that vitamin D supplementation was not recommended for patients with COVID-19.

Recommendation
There is insufficient evidence to recommend either for or against the use of vitamin D for the prevention or treatment of COVID-19.

Eleven cohort studies with 536,105 patients and two RCTs were identified. Vitamin D deficiency (< 20 ng/ml) or insufficiency (< 30 ng/ml) was not associated with an significant increased risk of COVID-19 infection (OR for < 20 ng/ml: 1.61, 95% CI: 0.92–2.80, I2 = 92%) or in-hospital death (OR for < 20 ng/ml: 2.18, 95% CI: 0.91–5.26, I2 = 72%; OR for < 30 ng/ml: 3.07, 95% CI: 0.64–14.78, I2 = 66%). Each 10 ng/ml increase in serum vitamin D was not associated with a significant decreased risk of COVID-19 infection (OR: 0.92, 95% CI: 0.79–1.08, I2 = 98%) or death (OR: 0.65, 95% CI: 0.40–1.06, I2 = 79%). The overall quality of evidence (GRADE) for COVID-19 infection and associated death was very low. Vitamin D supplements did not significantly decrease death (OR: 0.57, I2 = 64%) or ICU admission (OR: 0.14, I2 = 90%) in patients with COVID-19. The level of evidence as qualified using GRADE was low.

There is limited effect in the estimated effect: The true effect might be substantially different from the estimated effect.

Previous infection, followed by vaccination or booster is likely to increase the neutralization level and likely confer protection from severe disease in Omicron infection.

Previous infection, followed by vaccination or booster is likely to increase the neutralization level and likely confer protection from severe disease in Omicron infection

A clinical summary presented by a group of physicians and public health experts to the World Health Organization (WHO) has pointed to a sharp rise in hospital admissions in Covid-positive kids above the age of two in South Africa.