Shedding of Infectious SARS-CoV-2 Despite Vaccination when the Delta Variant is Prevalent – Wisconsin, July 2021

“Furthermore, individuals with vaccine breakthrough infections frequently test positive with viral loads consistent with the ability to shed infectious viruses …

“if vaccinated individuals become infected with the delta variant, they may be sources of SARS-CoV-2 transmission to others …

“data substantiate the idea that vaccinated individuals who become infected with the Delta variant may have the potential to transmit SARS-CoV-2 to others.”

“SARS-CoV-2-naïve vaccines had a 13.06-fold (95% CI, 8.08 to 21.11) increased risk for breakthrough infection with the Delta variant compared to those previously infected.” …

para 27 fold increased risk of symptomatic COVID and 8 fold increased risk of hospitalization (vaccinated over unvaccinated).

“vaccine effectiveness of BNT162b2 against infection waned progressively from 92% (95% CI, 92-93, P<0·001) at day 15-30 to 47% (95% CI, 39-55, P<0·001) at day 121-180, and from day 211 and onwards no effectiveness could be detected (23%; 95% CI, -2-41, P=0·07)”

…while the vaccine provides temporary protection against infection, the efficacy declines below zero and then to negative efficacy territory at approximately 7 months, underscoring that the vaccinated are highly susceptible to infection and eventually become highly infected (more so than the unvaccinated).

“BNT162b2-induced protection against infection appears to wane rapidly after its peak right after the second dose.”

Researchers reported “23 complete-genome sequences were obtained. They all belonged to the Delta variant, and were phylogenetically distinct from the contemporary Delta variant sequences obtained from community transmission cases, suggestive of ongoing transmission between the workers.

"Interpretation: Breakthrough Delta variant infections are associated with high viral loads, prolonged PCR positivity, and low levels of vaccine-induced neutralizing antibodies, explaining the transmission between the vaccinated people."

“The vaccinated had on average more virus in their nose than the unvaccinated who were infected.”

“secondary transmission occurred from those with symptomatic infections despite use of personal protective equipment (PPE).”

“The PPE and masks were essentially ineffective in the healthcare setting.

“The index cases were usually fully vaccinated and most (if not all transmission) tended to occur between patients and staff who were masked and fully vaccinated, underscoring the high transmission of the Delta variant among vaccinated and masked persons …

“this nosocomial outbreak exemplifies the high transmissibility of the SARS-CoV-2 Delta variant among twice vaccinated and masked individuals.”

Report # 44: PHE

Information on page 23 raises serious concerns when it reported that “waning of the N antibody response over time and (iii) recent observations from UK Health Security Agency (UKHSA) surveillance data that N antibody levels appear to be lower in individuals who acquire infection following 2 doses of vaccination.”

Also shows a pronounced and very troubling trend, which is that the “double vaccinated persons are showing greater infection (per 100,000) than the unvaccinated, and especially in the older age groups e.g. 30 years and above.”

“Examined the durability of immune responses to the BNT162b2 mRNA vaccine.

“They ‘analyzed antibody responses to the homologous Wu strain as well as several variants of concern, including the emerging Mu (B.1.621) variant, and T cell responses in a subset of these volunteers at six months (day 210 post-primary vaccination) after the second dose …’ data demonstrate a substantial waning of antibody responses and T cell immunity to SARS-CoV-2 and its variants, at 6 months following the second immunization with the BNT162b2 vaccine.”

Reported that “in the case of the Delta variant, neutralizing antibodies have a decreased affinity for the spike protein, whereas facilitating antibodies display a strikingly increased affinity.

“Thus, ADE may be a concern for people receiving vaccines based on the original Wuhan strain spike sequence (either mRNA or viral vectors).”

“Reported on the resurgence of SARS-CoV-2 infection in a highly vaccinated health system workforce.

“Vaccination with mRNA vaccines began in mid-December 2020; by March, 76% of the workforce had been fully vaccinated, and by July, the percentage had risen to 87%. Infections had decreased dramatically by early February 2021…

“coincident with the end of California’s mask mandate on June 15 and the rapid dominance of the B.1.617.2 (delta) variant that first emerged in mid-April and accounted for over 95% of UCSDH isolates by the end of July, infections increased rapidly, including cases among fully vaccinated persons…

“researchers reported that the “dramatic change in vaccine effectiveness from June to July is likely to be due to both the emergence of the delta variant and waning immunity over time.”

“Examined the transmission and viral load kinetics in vaccinated and unvaccinated individuals with mild delta variant infection in the community.

“They found that (in 602 community contacts (identified via the UK contract-tracing system) of 471 UK COVID-19 index cases were recruited to the Assessment of Transmission and Contagiousness of COVID-19 in Contacts cohort study and contributed 8145 upper respiratory tract samples from daily sampling for up to 20 days)

“‘vaccination reduces the risk of delta variant infection and accelerates viral clearance. Nonetheless, fully vaccinated individuals with breakthrough infections have peak viral load similar to unvaccinated cases and can efficiently transmit infection in household settings, including to fully vaccinated contacts.’”