Shamez Ladhani, United Kingdom

Public Health England Immunisation- Hepatitis and Blood Safety Department

Poster Author Of 1 e-Poster

Online Abstracts Vaccines - Impact of Vaccine programs and Serotype Replacement C2 Impact of Vaccine programs and Serotype Replacement

Author Of 5 Presentations

SEROTYPE REPLACEMENT IN ENGLAND: THE BIAS OF INCREASED REPORTING (ID 1231)

Session Name
Vaccines - Impact of Vaccine programs and Serotype Replacement

Abstract

Background

Increased incidence of invasive pneumococcal disease (IPD) attributable to non-vaccine serotypes (NVT) has been reported in several countries following introduction of PCV7 and PCV13 vaccines, concurrently with a reduction in vaccine-type IPD. Such serotype replacement has, importantly, emerged in England, offsetting the benefit of PCV introduction. We scrutinise most recent findings to assess if the estimated increase in NVT disease might result from surveillance artefacts.

Methods

Using IPD surveillance for 2000-2018, we estimate the impact of PCV7 and PCV13 introduction on age-serotype-specific incidence rates through a synthetic control regression model, building counterfactuals by combining age-specific incidences reported for pathogens unaffected by PCVs.

Results

Following the introduction of PCV7 and PCV13 (pre-2006 vs post-2011), total IPD incidence declined by 57% and by 76% in children younger than 5. PCV7-IPD decreased by 93% in all age groups, whereas PCV13-IPD declined by 68% since PCV13 was introduced. Importantly, NVT-IPD increased by 43% after PCV7, with non-significant statistical increases in most age groups.

Conclusions

Through appropriate statistical modelling, we disentangled the impact of vaccine and improved surveillance on the changes in IPD incidence rates. By controlling for the confounding effects of improved surveillance, we are able to estimate a lower serotype replacement.

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EFFECTIVENESS OF INFLUENZA VACCINATION AGAINST INVASIVE PNEUMOCOCCAL DISEASE IN THE ELDERLY ≥65 YEARS ELIGIBLE FOR VACCINATION IN ENGLAND AND WALES (ID 553)

Abstract

Background

The clinical and epidemiological studies conducted during the 1918 pandemic brought new evidence, with Influenza viruses recognised to induce Pneumonia and favour bacterial co-infections and secondary bacterial infections. Therefore, Influenza vaccination may protect against Pneumococcal outcomes by reducing the risk of influenza infection.

Methods

Screening method is used to measure VE. IPD cases were extracted from surveillance database with information on serotype, specimen date, age, clinical conditions, sex, PPV23 and Influenza vaccination dates. Influenza vaccine coverage was extracted from RCGP and matched to IPD cases based on age group (65-74, 75-84, ≥ 85), risk group, PPV23 vaccination, and weeks. The study period was September 2015 to June 2016.

Results

Overall crude Flu VE against IPD was 45% (39, 50). Matching IPD with RCGP proportion vaccinated, overall adjusted VE was 27% (19, 34) in 65+, 26% (14, 38) in 65-74 and 75-84, 28% (14, 40) in 85+ years old. Stratifying by time, VE was 24% (13-33) in January – April and 24% (00-42) in May - June.

Conclusions

Since VE against Influenza was 29% overall and 56% against H1N1 in the elderly in 2015/16 in UK, a very strong association between Influenza and IPD would be needed to have a 27% VE against IPD.

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PNEUMOCOCCAL CPE/EMPYEMA: A DIFFERENT DISEASE FROM OTHER RESPIRATORY INFECTION? (ID 648)

THE CLINICAL IMPACT OF STREPTOCOCCUS PNEUMONIAE SEROTYPE SHIFT TO NON-PCV13 VACCINE SEROTYPES (ID 699)

CASE FATALITY RATES ASSOCIATED WITH INVASIVE PNEUMOCOCCAL DISEASE DECLINED AFTER PCV13 IMPLEMENTATION IN ENGLAND (ID 1018)

Abstract

Background

The serotypes causing invasive pneumococcal disease (IPD) have changed significantly since the introduction of the 7-valent (PCV7) and 13-valent (PCV13) pneumococcal conjugate vaccines (PCV) in England. Since case fatality rate (CFR) varies across different pneumococcal serotypes, we analysed trends in deaths and CFR before and after implementation of the two PCV programmes in England

Methods

Public Health England conducts enhanced IPD surveillance in England. Cases and deaths occurring within 7 days of IPD diagnosis were used to calculate CFR during 2002/03-2018/19.

Results

The number of IPD deaths increased from 744 in 2005/16 just before PCV7 was implemented and peaked at 756 in 2009/10 just before PCV13 replaced PCV7 and then declined to 450 cases in 2013/14, when IPD cases were also at their lowest. Since then, IPD cases and deaths increased and peaked in 2018/19 before declining in 2018/19. CFR trends followed IPD deaths until 2008/09 peaking at 14.4% and then gradually declined to 9.9% in 2018/19. This was because the replacing serotypes after PCV13 implementation, especially serotypes 8 and 12F, were associated with lower age-adjusted CFR compared to PCV13 serotypes.

Conclusions

CFR declined only after PCV13 replaced PCV7 in 2010. The current replacing serotypes are associated with lower CFR than PCV13 serotypes.

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