Doc Hines - Covid News & Views - 18 March 2022
The number of Covid 19 tests being done continues to rise by about 10% week on week. For the last 7 days it is almost 5 million tests, actually 4,997,040. This is almost 450, 000 more than the previous week. The number testing positive grows every day. In the last week 552,198. This is a 38% increase on the previous week. Please, do remember some people have tested more than once. I have tested negative three times this week after a close contact with a case one week ago. I should be safe from that contact now. The positive rate has climbed steadily again and is 724.3 per 100,000 of the population.
I am hearing of a lot of cases recently, but they have been largely minor thanks to them having been fully vaccinated. Remember just how important this is.
The hospital data shows that 12,029 people have been admitted to hospital in the last 7 days. This is 2,390 more than in the previous week or a 25% rise in the number admitted.
Yesterday there were 14,671 people currently in a hospital bed and 292 were requiring mechanical ventilation.
There were 740 deaths reported in the last week , just 14 more than the previous week. The death rate is back at just 1 per 100,000. A good win on the national lottery is more likely.
The vaccine figures have remained unchanged for the last few days. We need another push to get those still reluctant to have their jab.
I have been reviewing the data on vaccines and their effectiveness. The statistics are not easy to digest but rest assured the vaccines have saved millions of lives.
Four Covid 19 vaccines have now been approved for use in the UK. Numerous rigorous clinical trials have been undertaken to understand how the immune process works as well as the safety and efficacy of these vaccines. These studies are all part of the process of each vaccine before they are approved for use. On going continuous monitoring is required as the vaccines are rolled out across the population to ensure that the clinical and Public Health guidance is based on the best available evidence. This monitoring is the responsibility of the UK Health Security Agency (UKHSA) which at first was known as Public Health England, working closely the Medicines and Healthcare Regulatory Agency (MHRA), NHS England, and other Government devolved administrations and academic partners. Their clear conclusion continues to be that overall, the benefits of Covid 19 vaccine outweigh any potential risks.
The assessment of the effectiveness of the vaccine in preventing people having the disease with symptoms is assessed in England by the National Immunisation Management System (NIMS), various Covid infection surveys and the GP electronic health record data. After 2 doses of Astra Zeneca vaccine the effectiveness started at between 45 and 50% and then dropped after about 20 weeks to almost no effect. With the Pfizer or Moderna vaccine effectiveness dropped from around 65-70% to 10% by 25 weeks after the second dose. When a booster dose of Pfizer or Moderna vaccine was given the effectiveness rose after 2-4 weeks back to 60-75%. It lasted a further 15 plus weeks before dropping back to 25-40% again.
Vaccine effectiveness for booster doses were very similar, irrespective of what the primary course was or whether they were mixed. Several studies have estimated vaccine effectiveness against hospitalisation in older ages, all of which indicate higher levels of protection from hospitalisation with all vaccines against the Alpha or Delta variant. With the Omicron variant the effectiveness against hospitalisation has been estimated using a test negative case control study design. 2 doses of AZ or Pfizer vaccines were associated with an effectiveness in preventing hospital admission of around 30% of people with the omicron variant after 25 weeks. After a third dose with Pfizer the effectiveness in preventing hospitalisation with Covid was up to 90%, dropping to 75% after 10-14 weeks. This was why most of us had Pfizer vaccine as a third dose.
As far as effectiveness against mortality was concerned all three vaccines gave very high levels of protection, over 90%. With Alpha and Delta variants, there was very little waning over time of protection from death.
Consider now transmission. The studies all confirm that vaccines are effective against infection. If you are not infected, you cannot transmit it, therefore vaccines do help to reduce transmission as well. There is probably additional evidence of reduced transmission as well due to reduced virus shedding and reduced duration of illness.
The overall vaccine effectiveness was slightly higher in younger compared to older age groups. All these immunity levels were remarkable considering the speed of development and them satisfying all the regulatory tests before approval was given for use.
Remember the basics, plan K will keep you safe. Please do not take risks. A friend of mine said “ if people I see tell me I need not wear a mask in the shops or on the tube I say do as you like. I am wearing mine, so I do not risk infecting you”. If you can, follow the facts above, if you are fully vaccinated your risks are very small. There is no need for fear the risks are so much better now compared to the beginning of the pandemic. Please stay safe.