Credit UK PHE/CMO
#16,109
Although it doesn't alter the fact that vaccines remain our best tool against the SARS-CoV-2 virus, there is no denying that vaccines are losing some of their effectiveness against the newer COVID variants like Delta, and we may see that trend continue as additional variants (like Epsilon, Lambda, and Beta) increase their global spread.
Additionally, studies show that your chances of being reinfected with COVID are far less if you are vaccinated than if you were only previously infected (MMWR: Reduced Risk of Reinfection with SARS-CoV-2 After COVID-19 Vaccination).Regardless of any loss of effectiveness against infection, vaccines continue to provide excellent protection against serious illness, hospitalization, and death from COVID.
Despite these clear benefits, and a very low (but admittedly, not zero) chance of serious side effects, getting vaccine hesitant people to take the vaccine hasn't been easy. And that gives the virus a decided advantage, and leaves society in a precarious position.
A week ago, in UK SAGE: Can We Predict the Limits of SARS-CoV-2 Variants and their Phenotypic Consequences?, we looked at four possible scenarios with COVID going forward; ranging from very bad (a much more lethal virus), to pretty bad (vaccine escape), to good (decreased virulence over time).
While we can't know what direction the COVID pandemic will take, the more hosts the virus infects, the more evolutionary opportunities the virus is afforded. And so far, that hasn't worked out particularly well for humans.
Today's report from Denmark's SSI finds the number of vaccine breakthrough infections by the Delta variant has increased markedly, but the vaccine still provides significant protection against severe illness, hospitalization, and death.
And even with an increased percentage of breakthrough cases, those who are fully vaccinated are still far less likely to be infected by the Delta variant - or pass it on to others - than those who are unvaccinated, or only partially vaccinated.
Today's reports suffers slightly in the fact that it is a machine translation - and that can occasionally introduce some vague syntax - and the link to the full study currently returns a 404 error.
Hopefully access to the study will be remedied quickly.
While it is hard to foresee a future where COVID no longer circulates, vaccines - even imperfect ones - can help us get to the point where we can reach a tenuous truce with the virus.
Larger proportion of covid-19 infections among vaccinated
New report on covid-19 infections after vaccination shows that the proportion of infected among vaccinated has increased after the delta variant has become dominant. Although several breakthrough infections are seen, there are still only a few admissions among the fully vaccinated.Last edited August 6, 2021
Since the Danish vaccination program against covid-19 began on 27 December 2020, the Statens Serum Institut (SSI) has been keeping an eye on infections after vaccination. Latest report includes data from December 27, 2020 until August 3, 2021.
Here you can read the new report on infections after vaccination.
The new report shows that a larger proportion of vaccinated people can be found among new infections with covid-19 since the last survey. The figures indicate that the delta variant, which became dominant in Denmark in July, is behind the increases.
In particular, the proportion of infected people who were first vaccinated has risen to now make up one tenth of all infected people. Breakthrough infections, ie infection among fully vaccinated people, are also on the rise, but remain at a low level.
Full vaccination continues to provide good protection against hospitalizations and deaths. The incidence of both in connection with breakthrough infections is stable and at a low level. However, you can still become infected when you are fully vaccinated and carry the infection with few or no symptoms.
It is therefore important that fully vaccinated people continue to participate in infection detection by being tested if they develop symptoms or if they are in close contact with infected people.
Larger proportion infected after 1st vaccination
The figures in the recently compiled report show that 17,532 infections have been found among people who have been vaccinated for the first time, but before the person has received another bite.
This corresponds to 10.8% of the total number of covid-19 infections. At the last calculation based on figures until the end of June, this share was 5.4%.
"There has been an increase in the proportion of infections after the first vaccination in our new inventory, this is due both to the fact that more people are vaccinated for the first time and that the 1st vaccine provides less protection against the delta variant, which has been dominant in July" says Tyra Grove Krause .
Fully vaccinated are well protected
SSI figures also show that 4,592 covid-19 cases were found after a person was vaccinated a second time. This corresponds to 2.8% of the total number of covid-19 infections.
3,702 out of the 4,592 cases have been found after the full effect of the vaccine has been introduced. They are therefore called breakthrough infections. The proportion of fully vaccinated people who have had a breakthrough infection is 0.13%.
"The probability of getting a breakthrough infection is very small, less than 2 out of 1000 fully vaccinated have been detected infected with covid-19 after being fully protected by a vaccination program," says Tyra Grove Krause, acting academic director at the Statens Serum Institut.
Low and stable number of hospitalizations and deaths after 2nd vaccination
Among the 3,702 covid-19 individuals with breakthrough infections, 197 were hospitalized within 14 days of a positive PCR test, and there were 47 deaths within 30 days of a positive PCR test.
According to SSI's figures, the number of hospitalizations and deaths has been fairly stable throughout the period when looking at the people who have had breakthrough infection.
We do not know the details of why the individuals have been hospitalized or have died. Therefore, the admissions and deaths cannot with certainty be attributed to covid-19, but since they occurred around the time of a positive PCR test, they are classified as covid-19 related.
"Fortunately, we see very few hospitalizations and deaths among fully vaccinated even after the delta variant has become dominant, it shows that the vaccines protect against serious processes," says Tyra Grove Krause.
Breakthrough infections for the delta variant
Breakthrough infections are expected to occur as no vaccines cover 100%. SSI also keeps a close eye on whether some of the many covid-19 variants increase the risk of becoming infected after being vaccinated.
The number of cases with the delta variant has been increasing in recent weeks, which has meant that the delta variant now accounts for the largest proportion of breakthrough infections.
About 9% of delta variant cases have been seen among people who are fully vaccinated, this is a higher proportion than for the other variants, but the delta variant has also spread at a time when a larger proportion of the population has been fully vaccinated, and that's part of the explanation, ”continues Tyra Grove Krause.
Results from a scientific study from England show a high vaccine efficacy against symptomatic covid-19 for both the alpha and delta variants of respectively. 93.7% and 88.0% after vaccination with two doses of Comirnaty® (Pfizer-BioNTech).
Vaccinated people who become infected can infect others
Data from abroad and preliminary data from Denmark indicate that fully vaccinated with breakthrough infections can still infect others.
"Fully vaccinated people who still become infected can, even if they are not very ill, still infect others. That is why it is important that fully vaccinated people with symptoms or vaccinated people who have had close contact with an infected person are still tested. ” emphasizes Tyra Grove Krause
While it is hard to foresee a future where COVID no longer circulates, vaccines - even imperfect ones - can help us get to the point where we can reach a tenuous truce with the virus.
Assuming of course, we are willing to use them.
