Antibody Dynamics of 2009 Influenza A (H1N1) Virus in Infected Patients and Vaccinated People in China

BACKGROUND: To evaluate the risk of the recurrence and the efficiency of the vaccination, we followed-up antibody responses in patients with the 2009 pandemic H1N1 influenza and persons who received the pandemic H1N1 vaccine in Guangzhou China. METHODS: We collected serum samples from 129 patients and 86 vaccinated persons at day 0, 15, 30, 180 after the disease onset or the vaccination, respectively. Antibody titers in these serum samples were determined by haemagglutination inhibition (HI) assay using a local isolated virus strain A/Guangdong Liwan/SWL1538/2009(H1N1). RESULTS: HI antibody positive rate of the patients increased significantly from 0% to 60% at day 15 (χ(2) = 78, P<0.001) and 100% at day 30 (χ(2) = 23, P<0.001), but decreased significantly to 52% at day 180 (χ(2) = 38, P<0.001), while that of vaccinated subjects increased from 0% to 78% at day 15 (χ(2) = 110, P<0.001) and 81% at day 30 (χ(2) = 0.32, P = 0.57), but decreased significantly to 34% at day 180 (χ(2) = 39, P<0.001). Geometric mean titers (GMT) of HI antibodies in positive samples from the patients did not change significantly between day 15 and day 30 (T = 0.92, P = 0.36), but it decreased significantly from 80 at day 30 to 52 at day 180 (T = 4.5, P<0.001). GMT of vaccinated persons increased significantly from 100 at day 15 to 193 at day 30 (T = 4.5, P<0.001), but deceased significantly to 74 at day 180 (T = 5.1, P<0.001). Compared to the patients, the vaccinated subjects showed lower seroconversion rate (χ(2) = 11, P<0.001; χ(2) = 5.9, P = 0.015), but higher GMT (T = 6.0, P<0.001; T = 3.6, P = 0.001) at day 30 and day 180, respectively. CONCLUSION: Vaccination of 2009 influenza A (H1N1) was effective. However, about half or more recovered patients and vaccinated persons might have lost sufficient immunity against the recurrence of the viral infection after half a year. Vaccination or re-vaccination may be necessary for prevention of the recurrence

Simultaneous detection of enterovirus-D68 and vaccine-related poliovirus 3 in the stool samples of a 5-month hospitalized child with acute respiratory disease: A case report

Human enterovirus (EV) infections can lead to various manifestations, with variable correlations between genotypes and symptoms. Human enterovirus D68 (EV-D68) was considered to be associated with acute respiratory disease and acute flaccid myelitis. In this short report, both EV-D68 and poliovirus 3 were detected in the stool of a hospitalized 5-month child who presented with acute respiratory symptoms and who was recently vaccinated with oral polio vaccine (OPV), using a metatranscriptomic high-throughput sequencing method. The nearly full-length genome sequences with complete open reading frames of EV-D68 and poliovirus 3 were assembled. One previously-reported neurovirulence-related amino acid substitution (T860N) in the EV-D68 VP1 region was observed, but the patient showed no neurological symptoms. More attention should be paid to EV-D68, and continuous multiple syndrome-based surveillance on non-polio enterovirus is called for

Impact of Interventions on Influenza A(H7N9) Virus Activity in Live Poultry Markets

There are constant exposure of influenza A(H7N9) virus from live poultry market for poultry workers and the general population, but rapid reduction of viable virus in the market setting can be achieved by market closure and disinfection. Our findings highlight the value in intensive surveillance in a natural live poultry market setting, to assess human infection risk at the human-animal interface and effect of control measures on virus activity

Monthly results of virologic surveillance for A(H7N9) virus in retail live poultry markets, wholesale live poultry markets and poultry farms in Guangzhou, China, April 2013–February 2014.

<p>Monthly results of virologic surveillance for A(H7N9) virus in retail live poultry markets, wholesale live poultry markets and poultry farms in Guangzhou, China, April 2013–February 2014.</p

Enrollment of surveillance sites of the virologic surveillance program for A(H7N9) in Guangzhou, China.

<p>Enrollment of surveillance sites of the virologic surveillance program for A(H7N9) in Guangzhou, China.</p

The general routes of live poultry transmission in Guangzhou, China.

<p>The general routes of live poultry transmission in Guangzhou, China.</p