A Prospective, Epidemiological Study to Assess the Disease Burden of Respiratory Syncytial Virus Associated, Suspected Lower Respiratory Tract Infections in Newborns, From 0 to 2 Years of Age and Risk of Development of Wheeze and Asthma From 0 to 6 Years of Age

The purpose of this study is to assess the incidence and associated healthcare utilization of RSV-associated, suspected LRTI in a general population of infants from birth up to 2 years of age, and also to assess the accuracy of a newly developed LRTI case definition and severity scale compared to two existing definitions. The study will also assess the population attributable risk percent of RSV LRTI on the development of wheeze and asthma from 0 to 6 years of age.

New born infants from various countries over the world will be followed up for up to two years for the occurrence of Lower Respiratory Tract Infections. Through active and passive surveillance, any suspected case will be identified, assessed during an examination visit and followed up until completion through a diary card. Full symptomology will be assessed during the examination visit. The disease course and all healthcare utilization will be subsequently collected through a two-week diary card and contact with ay healthcare providers involved in management of the disease. RSV detection will occur through quantitative PCR of collected nasal swabs. A baseline cord blood serum sample of all subjects and a follow-up blood serum sample from a sub-cohort will also be collected to assess antibody levels at various points in time and in relation to risk of RSV LRTI.

For extension period, pertaining to wheeze and asthma (Epoch 002): Subjects' parent(s)/LAR(s) will be asked to re-consent and subjects will be followed up through quarterly contacts up to the age of 6 years. Data collection will also occur from medical charts retrospectively for those who have a gap period between the end of the primary study and providing re-consent for the extension. The extension involves enrolment visit (at 2nd birthday \[on completion of primary study or as soon as possible thereafter\]) and quarterly surveillance contacts.

Eligibility Criteria:
Inclusion Criteria:

Before birth:

* Subject whose parent(s)/Legally Acceptable Representative(s) (LARs), in the opinion of the investigator, can and will comply with the requirements of the protocol.
* Written informed consent (including consent to obtain a cord blood sample at birth) obtained from the parent(s)/LAR(s) of the subject.

After Birth:

* Subject for whom updated and re-signed informed consent and confirmation of eligibility is available not later than 5 working days after birth.
* Cord blood sample collection of at least 3 mL, at birth.

For extension period:

* Subject is enrolled at a study site that is participating in the extension period follow-up.
* Subject whose parent(s)/LAR(s), in the opinion of the investigator, can and will comply with the requirements of the protocol.
* Written informed consent (or witnessed thumb printed consent in case of an illiterate subject) obtained from the parent(s)/LAR(s) of the subject.
* Previous participation in the primary study (from birth up to the age of 2 years).

Exclusion Criteria:

Before birth:

* Subject expected to become Child in care
* Subjects whose parent(s)/LAR(s) are below the age of 18 or the legal consenting age of the respective country if this is higher.

After Birth:

* Child in care
* Newborn with a gestational age of less than 28 weeks.
* Subjects with any congenital condition that will require an expected postnatal stay in hospital of more than 12 consecutive weeks.
* Subjects with major congenital defects or serious chronic illness limiting life expectancy to less than 5 years.
* Subjects with any confirmed or suspected immunosuppressive or immunodeficient condition (including positive infection with human immunodeficiency virus \[HIV\]), based on medical history, physical examination or positive test result.

For extension period:

• Child in care.