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Can the booster shot of COVID-19 vaccines defeat Omicron variant?
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Can the booster shot of COVID-19 vaccines defeat Omicron variant? Looking back at the CDC’s modeling of Delta in July, is it ridiculous?
1. Omicron begins to hit the U.S.
While Delta cases remain high or even growing, Omicron cases in the United States are also rising rapidly.
Although the proportion of Omicron in the CDC’s national statistics is still less than 5%, New York State, New Jersey and other places have exceeded 10% a few days ago.
Consistent with observations in many European countries, the number of Omicron cases doubles every 2-3 days. New York and Washington, D.C. have set new highs of cases since the epidemic.
Omciron began its impact on the United States at the time when the Christmas and New Year holidays were approaching .
Since the CDC’s “very reluctant” resumption of the indoor mask order at the end of July, the United States’ epidemic prevention thinking has long been in a state of “avoiding the most important but not the least” .
Any proposal that is close to the “Lockdown” will never be considered.
Any suggestion to maintain or increase social distancing (including the mask order) will remain in the inconspicuous corner in the most euphemistic way.
Even vaccination is almost like “pick a soft persimmon”-don’t be “hard” with people who have not been vaccinated, and choose to say “let’s get the third shot” to those who have been vaccinated.
Could this kind of “appeasement” policy be successful for Omicron, who is about to come? Can the third shot of the mRNA vaccine be used to deal with Omicron’s winter?
2. Refer to the Delta modeling that has ignited public opinion
In July this year, CDC’s internal document discussing the threat of Delta was exposed by the Washington Post.
The document predicted that if the indoor mask order is not restored, vaccination alone will not be able to control the spread of Delta. This revelation caused an uproar in public opinion at the time.
There are documents epidemic modeling Delta, according to the vaccine efficacy , immunization coverage , the degree of protection of the population due to infection with the past and the D ability to communicate elta of these four parameters, add a mask so stringent, to analyze the epidemic control In the possibility of a non-burst state , some simulation results are shown in the figure below.
One of the most ideal conditions in the modeling is: Facing Delta’s super transmission power (R0=5), suppose:
- 35% of people have natural immunity due to past infections and will not be infected again
- 50% of people in the U.S. are vaccinated with a vaccine that is 75-85% effective against infection
- Full implementation of the indoor mask order
- There are no other requirements and measures to increase social distancing such as stay-at-home orders
As a result, there will be a 50% probability that the number of new cases per week will be controlled below 50 per 100,000 people-this standard corresponds to moderate transmission, that is, the epidemic is not a major outbreak.
Soon the CDC recommended that people wear masks indoors regardless of whether they have been vaccinated or not. This is also based on this.
We can compare the situation with Omicron.
- Omicron spreads as fast as Delta
- Due to immune escape, past infections are not effective in blocking Omicron. There is no 35% of people who will not be infected because of natural immunity
- According to the study of the British Public Health Department, the effectiveness of the mRNA vaccine to enhance the prevention of symptomatic COVID-19s is about 75% . Note that the tracking time is not long after the vaccination, and the possibility that the effectiveness will be lower over time is not ruled out. The effectiveness of the two-shot mRNA vaccine is about 30% or even lower according to studies in the United Kingdom and South Africa.
- The percentage of completed vaccination in the United States is 61.2% . If it is assumed that Omicron infection can only be dealt with after a booster shot (equivalent to a 75% effective vaccine), 60 million people in the United States have been vaccinated with booster shots , accounting for about 18.2% of the population .
All key parameters are weaker (or even far weaker) than the assumptions in Delta modeling. Excuse me, how can the United States contain Omicron only by encouraging booster shots?
In addition, the United States obviously did not follow the model envisaged to prevent the Delta outbreak only by restoring the mask order. P
ossible reasons include overestimation of the effectiveness of vaccines and natural immunity against infection, and the actual implementation of mask orders.
It can be seen that this model is an optimistic model and is by no means overly conservative. If you are far from an optimistic model assumption, how far is it from success?
3. Can I only look at severe cases?
The above model discusses the containment of new cases. Should we turn our attention to severe illness or hospitalization instead of worrying about whether the infection cases are controllable?
In principle, there is no problem. I also very much agree with one sentence, that is, “The goal of epidemic prevention, including vaccination, should not be to cure all colds.”
However, paying more attention to severe cases does not mean that infections are meaningless.
In particular, according to the current trends and characteristics of Omicron, the data for severe illness and hospitalization is likely to be only a few weeks later than the infection case .
If you have the fluke that “there are not many serious illnesses anyway,” then it is likely that you are just doing an ostrich with your head buried in the sand.
First of all, the starting point for US hospitalization data is very bad . Because of Delta, the number of cases in the United States has been increasing, and hospitalizations have also been increasing.
According to CDC statistics, an average of 7,814 new hospitalizations were added every day from December 8 to 14, which was an average increase of 4.4% over the previous week.
This is only because of Delta, the entire medical system does not have much redundancy for Omicron to “spend”.
Second, the spread of Omicron has greatly increased the threat of severe illness . An enduring misunderstanding is that Omicron’s symptoms are mild and there is no threat of severe illness.
This is very absurd blind optimism. Recently, Denmark and the United Kingdom respectively released some preliminary Omicron hospitalization data.
It was found that the hospitalization risk of Omicron is similar to Delta when the infected person has similar background conditions (such as vaccination, age, etc.).
Even assuming that the risk of Omicron’s hospitalization is 50% lower than that of Delta, which is already 30% less hospitalized than the often misunderstood South Africa, it is an even more optimistic assumption.
To see that Delta doubles the number of cases in 2-3 weeks, Omicron is 2- 3 days .
The number of cases at the same starting point, after 2 weeks, Omicron’s cases are at least 8 times that of Delta , and the total number of hospitalizations is 4 times .
Third, the decline in the effectiveness of existing vaccines and monoclonal antibody drugs will reduce our ability to reduce the risk of Omicron’s hospitalization .
According to data from South Africa, the effectiveness of two doses of Pfizer vaccine to protect Omicron from hospitalization is 70%. Yes, this proves that the existing vaccines are still very effective for severe cases.
However, this effective number is much lower than the 80% or more than 90% critical illness protection in the past Delta period.
In addition to vaccines, monoclonal antibody drugs are now the most important means to reduce hospitalizations for COVID-19.
The two antibody drugs with the largest supply in the world, Eli Lilly and Regeneron, have clearly failed to Omicron.
The only US that can deal with Omicron is the antibody between GSK and Vir. According to the US HHS, all 55,000 doses of the stock will be distributed next week, but there will be no more drugs available before January.
In summary, if it is not controlled, Omicron is very likely to cause severe illness and a substantial increase in hospitalization .
However, we have little room for maneuver to face this increase, and the tools to deal with it are also decreasing.
4. Vaccines are important, but not enough
How to deal with Omicron?
Vaccination, including the booster injection of mRNA vaccine, is still the most effective measure to minimize severe illness and hospitalization, and it is naturally a key means to deal with Omicron .
From a personal point of view, vaccination is the best way to reduce the risk of severe illness and hospitalization after infection. Yes, the effectiveness of the vaccine is not as good as before.
However, in the face of a mutant strain that doubles every two days, the risk of infection for anyone is very high.
The difference between the vaccine and the vaccine is: when you are infected, you are Do you want to reduce the risk of hospitalization by 70% or not at all?
The benefits of booster shot are also obvious. The effectiveness of reducing the risk of symptomatic infection by 75% is not as good as before, but this is much better than the 30% of two needles.
More importantly, it is likely to increase the effectiveness of the two injections to prevent hospitalization by 70%.
The benefit of the third shot is definitely not as big as the first two shots, but for people who have already received two shots, this may be the most profitable thing that can be done .
However, from the overall perspective of epidemic prevention, if the United States only recommends the third shot, it is obviously not enough .
First, as we have just analyzed, due to the peak of the epidemic caused by Delta, the US medical system does not have much redundancy to deal with Omicron.
Therefore, it is necessary to control the number of Omicron cases-although the substantial increase in Omicron cases is almost destined, it is still necessary to control its increase .
Second, with the existing vaccines, even if the booster is included, it is still difficult to control the increase in Omicron .
Just as we put Omicron’s data into the CDC modeling for Delta in July, we can see that it wo n’t work without more physical epidemic prevention measures .
One is that even if the booster is included in the vaccine, its effectiveness is still insufficient .
In less than a week, public figures who still had a breakthrough infection after the booster shot included the CEO of Southwest Airlines, Senator Warren of Massachusetts, and Senator Booker of New Jersey.
At present, vaccines are very good at preventing severe illnesses, but in the face of the high amount of virus in the environment brought about by the surge of cases around, the prevention of infection is stretched.
The more critical point is that the vaccination rate is still too low .
The percentage of completed vaccination in the United States is 61.2%, and the coverage rate of booster shot is 18.2%.
This vaccination rate is not enough to deal with Delta, and it is not enough to deal with Omicron.
The current attitude of the United States towards vaccination is to greatly promote and strengthen the needle.
This kind of publicity is no problem and necessary (of course, in my opinion, the content itself is not very good).
Successful propaganda needs to give the public a clear direction . How many people have been vaccinated with booster shots that can make a substantial difference in controlling the epidemic? How many new hospitalizations are added every day? What is the goal? To achieve this goal, how far is the vaccination rate?
When the United States encourages vaccination, it is good to just say that booster shots are good. But what do people see? A total of 100 senators were infected with two booster shots in a single weekend.
Is this vaccine as good as you said? Unclear status and goals. What the public sees is that you have promoted one-year vaccination, and the number of shots to be given has increased with the number of cases. How can you be convinced?
In the same way to promote booster shots, the United Kingdom clearly stated when it intends to complete comprehensive coverage, how many people need to be vaccinated a day for such coverage, and how to allocate resources to achieve this.
The United States just calls you to fight, and counts one by one. This kind of thinking is used for individuals. It is true that the best protection for individuals is achieved by individual vaccination, but for a global policy, where does this go? The practice there is very absurd.
The government needs to have clear and objective analysis and communication on the epidemic. When the Indian epidemic broke out in April and May, India was also planning to speed up vaccination.
Faucci’s assessment at the time was that for such an outbreak period, vaccination was not enough to catch up, and more physical epidemic prevention measures would take effect.
The United States faces Omicron similarly. The number of cases has doubled in two or three days. Less than 20% of the population have been vaccinated with booster shots .
It is impossible to increase the vaccination rate of booster shots and improve immune protection. Time is too late .
Strict physical epidemic prevention measures are indeed the least welcomed by Europeans and Americans.
However, decision-making cannot be avoided because the virus does not care about the difficulty of your implementation or the approval rate of public opinion.
Blindly stalling may even happen that the virus executes for you-due to the surge in cases in New York, Broadway has recently been forced to suspend performances, and sports events such as the NFL and NBA have also changed their schedules due to a large number of player infections.
Since the reversal of the epidemic caused by Delta, the United States has proposed several response policies, which are generally to continue vaccination, increase the scope of booster needles, and prepare therapeutic drugs. But without clear goals and practical plans, these “policies” will inevitably become empty slogans.
On December 21st, Biden will once again release a policy update to respond to Omicron.
However, if the goal and current situation of the epidemic prevention are not clarified, there are no measures that have the ability to implement-such as adopting more restrictions on public activities for people who have not been vaccinated, including intensified injections in the definition of complete vaccination, and not adding more extensive measures-more Strict mask orders, reducing group activities, and reiterating the importance of social distancing, so the so-called “New Deal” are nothing more than clichés.
Can the booster shot of COVID-19 vaccines defeat Omicron variant?
(source:internet, reference only)