Update on Covid providing information on positivity and hospital admissions for England and its regions. This post is best viewed using the browser or Substack app.
Thank you Bob. In your appendix you set out how positivity rate can be used as a proxy for general prevalence. Could you say a bit more about this? As a non statistician the graphs suggest to me that prevalence is around a half of the positivity rate. Is that pushing the data too far? For practical purposes in assessing my personal exposure risk over time it would be useful to have your guidance on this, in the absence of government survey data
Edmund, the original intent of the appendix was to clarify the difference between test positivity and prevalence as some readers had incorrectly interpreted positivity as the percent of people in the general population.
Concerning your question, I think that using a direct relationship to estimate prevalence in the general population from test positivity is pushing the data a bit too far. Although I can understand why you would want to do so in the absence of any other data to assess your personal risk.
The reason I say this is because test positivity is based on people entering hospital for respiratory infections. These individuals are primarily over 65 years old and, as recently they are likely to have been regularly 'boosted', their immunity levels are changing over time. The 'waxing and waning' of immunity levels for this group will inevitably change the relationship between the test positivity data reported and prevalence in the general population over time.
Having said all that, I think test positivity is a useful indicator of the overall direction of travel for prevalence in the wider population which should guide your risk assessment when read in combination with the hospital admission data.
As of last week, I would say that the Covid risk is rising but is still relatively low. We'll find out more this Thursday if that remains the case.
Thank you for taking the time to explain further Bob. This, and all the work of Independent SAGE is greatly appreciated. I guess I am just hankering for the days of appropriately funded public health...
You stress the importance of the Spring 2024 booster campaign to protect the most vulnerable but how effective is the XBB 1.5 vaccine which is being administered against the new JN.1 lineage? The WHO Technical Advisory Group on COVID-19 Vaccine Composition has advised the use of a monovalent JN.1 lineage as the antigen in future formulations of COVID-19 vaccines but I am not sure when this updated vaccine will become available.
The UKHSA data discussed in the article above indicates the incremental effectiveness of the Pfizer XBB 1.5 and BA.4-5 vaccines against hospitalisation. The analysis, which was conducted during the prevalence of the original JN.1 variant, suggests that for individuals over 65, the incremental effectiveness of the vaccine is approximately 50% after two weeks, but it drops substantially after 15 weeks.
Recently, a new variant derived from the JN.1 family has emerged called KP.2 (or FLiRT) and very early research indicates that the current vaccines may not protect against the KP variants as well as they did against previous variants. As these JN derived variants are now certain to dominate, WHO has recommended the vaccine manufacturers to update their vaccines.
Having said that the current vaccines do offer some protection against serious disease so are worth taking for those at higher risk.
Not my area of expertise but I have not seen any published dates for when a new Covid vaccine updated for the JN.1 variant will be available.
What we do know is that it took about 9 months for the first vaccine to be authorised that targeted the Omicron (XBB 1.5) variant from when it was first identified. Production and distribution would then need to be scaled up.
Based on this history, I would guess that there won't be a widely available 'JN.1' based vaccine until Q3/4 2024, but it really is only a guess.
Thank you for the updates! Do you know if there’s any data, past or present about Covid vaccines helping with Long Covid symptoms? I remember there was talk of it a while back, but I’m not sure if it was studied in depth. Thanks.
Thank you for continuing to provide this information. What has struck me for quite a while is how the data seems to focus on age and the lack of information about people who are vaccine-eligible because of illness or disability. And I think the immunocompromised deserve a special mention in government data, instead their needs are largely ignored by society.
You are right that the data available seldom mentions those who are immunosuppressed. One of the reasons for this is that there is no national register of individuals who are immunosuppressed as this data is held at the GP level only. This makes it difficult, but not impossible, to collate Covid related information at that level.
Incidentally, identifying the immunosuppressed individuals to contact was a problem for the early booster campaigns which were more centrally managed. As GPs are now responsible for boosters this should not be an issue.
Given the risk to immunocompromised individuals, should there be a national register? Should it be part of pandemic preparedness, how were individuals identified for shielding? There also seems to be a lack of data on other under-65s who are eligible for boosters, the government only seems to produce stats on uptake amongst over-65s. Do the sick, the disabled and those who care for them not matter?
Hopefully the Covid Inquiry will be looking at the need for a national register as recommended by the APPG on Vulnerable Groups to Pandemics. See following link:
Individuals were identified for shielding by UKHSA based on clinical risks identified by the CMO and this was used by UKHSA to create a national Shielded Patient List. However, this stopped being updated in Sep 2021.
Finally, NHS England does publish information on booster coverage for immuno-suppressed under-65s by age at the end of campaigns, but it's not widely publicised. I recently did a post that included this data that can be found at the following link.
Thanks for the links. So they do have some kind of data about immuno-suppressed vaccine take up, pity it is not front and centre. I hope the Covid Enquiry bears fruit.
Re the poor take up, the government stance from summer 2021 seems to have induced a cloud-cuckoo-land situation where a lot of people believe that Covid is no longer harmful, or at the very least that nothing bad will happen to them.
Thank you for the updates and explanations. After a period of calm, I have started to see in the last two weeks a new round of Covid infections in family and friends so I wondered if a new wave was on its way...
It's encouraging to know the updates are useful, but it's important to note that currently, our data is solely from hospital admissions, which are a lagging indicator. Generally, hospital data reflects trends in the general population's Covid prevalence approximately a week after they occur.
It remains to be seen if these recent increases become a significant 'wave' as we don't really know what is driving the increases. It could be due to any combination of a new variant, waning immunity, or April's poor weather keeping more people indoors.
Thank you Bob. In your appendix you set out how positivity rate can be used as a proxy for general prevalence. Could you say a bit more about this? As a non statistician the graphs suggest to me that prevalence is around a half of the positivity rate. Is that pushing the data too far? For practical purposes in assessing my personal exposure risk over time it would be useful to have your guidance on this, in the absence of government survey data
Edmund, the original intent of the appendix was to clarify the difference between test positivity and prevalence as some readers had incorrectly interpreted positivity as the percent of people in the general population.
Concerning your question, I think that using a direct relationship to estimate prevalence in the general population from test positivity is pushing the data a bit too far. Although I can understand why you would want to do so in the absence of any other data to assess your personal risk.
The reason I say this is because test positivity is based on people entering hospital for respiratory infections. These individuals are primarily over 65 years old and, as recently they are likely to have been regularly 'boosted', their immunity levels are changing over time. The 'waxing and waning' of immunity levels for this group will inevitably change the relationship between the test positivity data reported and prevalence in the general population over time.
Having said all that, I think test positivity is a useful indicator of the overall direction of travel for prevalence in the wider population which should guide your risk assessment when read in combination with the hospital admission data.
As of last week, I would say that the Covid risk is rising but is still relatively low. We'll find out more this Thursday if that remains the case.
Hope that helps.
Bob
Thank you for taking the time to explain further Bob. This, and all the work of Independent SAGE is greatly appreciated. I guess I am just hankering for the days of appropriately funded public health...
You stress the importance of the Spring 2024 booster campaign to protect the most vulnerable but how effective is the XBB 1.5 vaccine which is being administered against the new JN.1 lineage? The WHO Technical Advisory Group on COVID-19 Vaccine Composition has advised the use of a monovalent JN.1 lineage as the antigen in future formulations of COVID-19 vaccines but I am not sure when this updated vaccine will become available.
Clare,
The UKHSA data discussed in the article above indicates the incremental effectiveness of the Pfizer XBB 1.5 and BA.4-5 vaccines against hospitalisation. The analysis, which was conducted during the prevalence of the original JN.1 variant, suggests that for individuals over 65, the incremental effectiveness of the vaccine is approximately 50% after two weeks, but it drops substantially after 15 weeks.
Recently, a new variant derived from the JN.1 family has emerged called KP.2 (or FLiRT) and very early research indicates that the current vaccines may not protect against the KP variants as well as they did against previous variants. As these JN derived variants are now certain to dominate, WHO has recommended the vaccine manufacturers to update their vaccines.
Having said that the current vaccines do offer some protection against serious disease so are worth taking for those at higher risk.
Bob
Do we know when the updated vaccine will become available?
Clare,
Not my area of expertise but I have not seen any published dates for when a new Covid vaccine updated for the JN.1 variant will be available.
What we do know is that it took about 9 months for the first vaccine to be authorised that targeted the Omicron (XBB 1.5) variant from when it was first identified. Production and distribution would then need to be scaled up.
Based on this history, I would guess that there won't be a widely available 'JN.1' based vaccine until Q3/4 2024, but it really is only a guess.
Thank you for the updates! Do you know if there’s any data, past or present about Covid vaccines helping with Long Covid symptoms? I remember there was talk of it a while back, but I’m not sure if it was studied in depth. Thanks.
Thank you for continuing to provide this information. What has struck me for quite a while is how the data seems to focus on age and the lack of information about people who are vaccine-eligible because of illness or disability. And I think the immunocompromised deserve a special mention in government data, instead their needs are largely ignored by society.
Fiona,
You are right that the data available seldom mentions those who are immunosuppressed. One of the reasons for this is that there is no national register of individuals who are immunosuppressed as this data is held at the GP level only. This makes it difficult, but not impossible, to collate Covid related information at that level.
Incidentally, identifying the immunosuppressed individuals to contact was a problem for the early booster campaigns which were more centrally managed. As GPs are now responsible for boosters this should not be an issue.
Bob Hawkins
Given the risk to immunocompromised individuals, should there be a national register? Should it be part of pandemic preparedness, how were individuals identified for shielding? There also seems to be a lack of data on other under-65s who are eligible for boosters, the government only seems to produce stats on uptake amongst over-65s. Do the sick, the disabled and those who care for them not matter?
Hopefully the Covid Inquiry will be looking at the need for a national register as recommended by the APPG on Vulnerable Groups to Pandemics. See following link:
https://www.bmj.com/content/376/bmj.o528
Individuals were identified for shielding by UKHSA based on clinical risks identified by the CMO and this was used by UKHSA to create a national Shielded Patient List. However, this stopped being updated in Sep 2021.
Finally, NHS England does publish information on booster coverage for immuno-suppressed under-65s by age at the end of campaigns, but it's not widely publicised. I recently did a post that included this data that can be found at the following link.
https://bhawkins3.substack.com/p/what-lessons-can-we-learn-from-the
Vaccine coverage for the immuno-suppressed under-65s is worryingly low.
Bob
Thanks for the links. So they do have some kind of data about immuno-suppressed vaccine take up, pity it is not front and centre. I hope the Covid Enquiry bears fruit.
Re the poor take up, the government stance from summer 2021 seems to have induced a cloud-cuckoo-land situation where a lot of people believe that Covid is no longer harmful, or at the very least that nothing bad will happen to them.
Thank you for the updates and explanations. After a period of calm, I have started to see in the last two weeks a new round of Covid infections in family and friends so I wondered if a new wave was on its way...
Emma,
It's encouraging to know the updates are useful, but it's important to note that currently, our data is solely from hospital admissions, which are a lagging indicator. Generally, hospital data reflects trends in the general population's Covid prevalence approximately a week after they occur.
It remains to be seen if these recent increases become a significant 'wave' as we don't really know what is driving the increases. It could be due to any combination of a new variant, waning immunity, or April's poor weather keeping more people indoors.
Bob Hawkins